Peptidase inhibitors

ABSTRACT

This invention relates to analogs of peptidase substrates in which the amide group containing the scissile amide bond of the substrate peptide has been replaced by an activated electrophilic ketone moiety. These analogs of the peptidase substrates provide specific enzyme inhibitors for a variety of proteases, the inhibition of which will have useful physiological consequences in a variety of disease states.

This is a division of application Ser. No. 08/248,847, filed May 25,1994, now U.S. Pat. No. 5,496,927, granted Mar. 5, 1996; which is acontinuation of application Ser. No. 08/102,522, filed Aug. 4, 1993, nowabandoned; which is a continuation of application Ser. No.07/980,141,filed Nov. 23, 1992, now abandoned; which is a continuation ofapplication Ser. No. 07/540,033, filed Jun. 19, 1990, now abandoned,which is a continuation in part of application Ser. No. 07/372,162,filed Jun. 27, 1989, now abandoned; which is a continuation ofapplication Ser. No. 07/267,758, filed Nov. 1, 1988, now abandoned;which is a continuation of application Ser. No. 06/874,721, filed Jun.16, 1986, now abandoned; which is a continuation in part of applicationSer. No. 06/697,987, filed Feb. 4, 1985, now abandoned; which is hereinincorporated by reference.

This invention relates to protease enzyme inhibitors useful for avariety of physiological end-use applications.

In its broad aspects, this invention relates to analogs of peptidasesubstrates in which the amide group containing the scissile amide bondof the substrate peptide has been replaced by an activated electrophilicketone moiety such as fluoromethylene ketone or -keto carboxylderivatives. These analogs of the peptidase substrates provide specificenzyme inhibitors for a variety of proteases, the inhibition of whichwill have useful physiological consequences in a variety of diseasestates. In its more specific aspects, this invention relates toactivated electrophilic ketone derivatives of certain peptidasesubstrates which are useful in inhibiting serine-, thiol-, carboxylicacid- and metallo- dependent protease enzymes, the inhibition of whichwill have useful physiological consequences in a variety of diseasestates.

Still more specifically, this invention relates to activatedelectrophilic ketone derivatives of peptidase substrates which fallwithin the following generic groupings characterized according to theiractive site dependencies. Such generic groupings are:

I. Serine Dependent Enzymes: These include such enzymes as Elastase(human leukocyte), Cathepsin G, Thrombin, Plasmin, C-1 Esterase, C-3Convertase, Urokinase, Plasminogen Activator, Acrosin, β-Lactamase,D-Alanine-D-Alanine Carboxypeptidase, Chymotrypsin, Trypsin andKallikreins.

II. Thiol Dependent Enzymes: Cathepsin B.

III. Carboxylic Acid Dependent Enzymes: These include such specificenzymes as Renin, Pepsin and Cathepsin D.

IV. Metallo Dependent Enzymes: These include Angiotensin ConvertingEnzyme, Enkephalinase, Pseudomonas Elastase and Leucine Aminopeptidase.

The contemplated peptidase inhibitors of the foregoing enzymes areselected from the generic formula ##STR1## including the hydratesthereof, and the pharmaceutically acceptable salts thereof wherein Xembraces subgroups X₁ and X₂, wherein

X₁ is --CF₂ H, --CF₃, CO₂ R₃ or --CONHR₃, and

X₂ is ##STR2## R₂ is the side chain of the α-amino acid responsible fordirecting the inhibitor to the active site of the enzyme,

R₁ is H, an amino protecting group selected from Group K, an α-aminoacid or a peptide having up to 4 α-amino acids sequenced in their P₂ toP₅ position, the terminal amine of said α-amino acid or peptideoptionally bearing a protecting group selected from Group K,

R₃ may be H, C₁₋₄ straight or branched alkyl, phenyl, cyclohexyl,cyclohexylmethyl or benzyl,

R₄ is a side chain of an α-amino acid for that peptidase substrateanalog,

R₅ is an α-amino acid or peptide having up to 3 α-amino acids sequencedin their P₂ to P₄ positions, or is deleted, (sometimes herein stated "oris zero", and

Y is NHR₃ or OR₃,

with the proviso that when R₂ is a side chain of an α-amino acid ofGroup E and the R₁ moiety bears a member of Group D in its P₂ position,then X is other than CF₃.

Unless otherwise stated the α-amino acids of these peptidase substratesare preferably in their L-configuration.

Before further defining and/or illustrating the scope of the peptidasesubstrate inhibitors embraced by formula I, it may be convenient tostate some of the more basic concepts related to peptides. For example,except for proline, all of the α-amino acids found in proteins have, asa common denominator, a free carboxyl group and a free unsubstitutedamino group on the α-carbon atom (in proline, since proline's α-aminogroup is substituted it is really an α-imino acid, but for convenience,it will also be spoken of as an α-amino group). Additionally eachα-amino acid has a characteristic "R-group", the R-group being theside-chain, or residue, attached to the α-carbon atom of the α-aminoacid. For example, the R-group side chain for glycine is hydrogen, foralanine it is methyl, for valine it would be isopropyl. (Thus,throughout this specification the R₂ or R₄ moiety is the side-chain foreach indicated α-amino acid). For the specific side chains of theα-amino acids reference to A. L. Lehninger's text on Biochemistry (seeparticularly Chapter 4) would be helpful.

As a further convenience for defining the scope of the compoundsembraced by the generic concept of Formula I, as well as the sub-genericconcepts relating to each of the individual enzymes involved in thisinvention, various α-amino acids have been classified into a variety ofgroups which impart similar functional characteristics for each of thespecific enzymes to be inhibited by the peptidase substrates of FormulaI. These groups are set forth in Table II and the recognizedabbreviations for the α-amino acid blocks are set forth in Table I.

                  TABLE I                                                         ______________________________________                                        Amino Acid              Symbol                                                ______________________________________                                        Alanine                 Ala                                                   Arginine                Arg                                                   Asparagine              Asn                                                   Aspartic acid           Asp                                                   Asn + Asp               Asx                                                   Cysteine                Cys                                                   Glutamine               Gln                                                   Glutamic acid           Glu                                                   Gln + Glu               Glx                                                   Glycine                 Gly                                                   Histidine               His                                                   Isoleucine              Ile                                                   Leucine                 Leu                                                   Lysine                  Lys                                                   Methionine              Met                                                   Phenylalanine           Phe                                                   Proline                 Pro                                                   Serine                  Ser                                                   Threonine               Thr                                                   Tryptophan              Trp                                                   Valine                  Val                                                   Norvaline               n-Val                                                 n-Leucine               n-Leu                                                 1-Naphthylalanine       Nal (1)                                               2-Indolinecarboxylic Acid                                                                             Ind                                                   Sarcosin                Sar                                                   ______________________________________                                    

                  TABLE II                                                        ______________________________________                                        Group A:                                                                             Lys and Arg                                                            B:     Glu, Asp                                                               C:     Ser, Thr, Gln, Asn, Cys, His                                           D:     Pro, Ind                                                               E:     Ala, Leu, Ile, Val, n-Val, Met, n-Leu and N-methyl                            derivatives                                                            F:     Phe, Tyr, Trp, Nal (l), and N-methyl derivatives                       G:     Gly, Sar                                                               J:                                                                                    ##STR3##                                                                      ##STR4##                                                                      ##STR5##                                                                      ##STR6##                                                                     with φ representing phenyl                                         K:     Acetyl (Ac) Acetyl (Ac) Succinyl (Suc), Benzoyl (Bz)                          t-Butyloxycarbonyl (Boc), Carbobenzoxy (CBZ), Tosyl                           (Ts), Dansyl (DNS), Isovaleryl (Iva),                                         Methoxysuccinyl (MeOSuc), 1-Adamantanesulphonyl                               (AdSO.sub.2), 1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl                     (2-CBZ) and such other terminal equivalent thereto.                    ______________________________________                                    

In light of the foregoing, the defined compounds of formula I may alsobe stated as being:

An activated electrophilic ketone-bearing peptidase inhibitor of theformula ##STR7## the hydrates thereof, and the pharmaceuticallyacceptable salts thereof wherein

R₁ is H, an amino protecting group selected from Group K, an α-aminoacid or a peptide having up to 4 α-amino acids sequenced in their P₂ toP₅ position, the terminal amine of said α-amino acid or peptideoptionally bearing a protecting group selected from Group K,

R₂ is the side chain of an α-amino acid,

X is X₁ or X₂ wherein

X₁ is CF₃, CF₂ H, CO₂ R₃ or --CONHR₃, and

X is ##STR8## R₃ is hydrogen, C₁₋₄ straight or branched alkyl, phenyl,benzyl, cyclohexyl or cyclohexylmethyl,

R₄ is the side chain of an α-amino acid,

R₅ is an α-amino acid or a peptide having up to 3 α-amino acidssequenced in their P₂ to P₄ positions, or is deleted,

Y is --NHR₃ or --OR₃

with the proviso that when R₂ is a side chain of an α-amino acid ofGroup E and the R₁ moiety bears a member of Group D in its P₂ position,then X is other than CF₃,

wherein the said α-amino acid and peptide moieties are building blocksselected from Groups, A, B, C, D, E, F, G, J and K is a terminal aminoprotecting group, members of these groups being

Group A: Lys and Arg,

B: Glu and Asp,

C: Ser, Thr, Gln, Asn, Cys and His,

D: Pro, Ind,

E: Ala, Leu, Ile, Val, n-Val, Met and n-Leu, and N-methyl derivatives,

F: Phe, Tyr and Trp, Nal (1), and N-methyl derivatives,

G: Gly, Sar,

J: ##STR9## with Φ representing phenyl. K: Acetyl (Ac) Succinyl (Suc),Benzoyl (Bz) t-Butyloxycarbonyl (Boc), Carbobenzoxy (CBZ), Tosyl(Ts),Dansyl (DNS), Isovaleryl (Iva), Methoxysuccinyl (MeOSuc),1-Adamantanesulphonyl (AdSO₂), 1-Adamantaneacetyl (AdAc),2-Carboxybenzoyl (2-CBZ) and such other terminal amino protecting groupswhich are functionally equivalent thereto.

To illustrate those compounds which are useful as enzyme inhibitors forhuman leukocyte elastase, and to serve as a medium of instruction for abetter understanding of the scope of compounds embraced within thegeneric formula I, (and its sub-generic formulae for each of theinvolved enzymes herein disclosed) the following formula (Ia) representsthe subgeneric class defining those compounds within the scope ofinhibitors of human leukocyte elastase: ##STR10## wherein R₂ is the sidechain of the depicted enzyme-directing α-amino acid (P1),

R₁ is as previously defined (Comprised of P₂ -P_(n) blocks), and

X is the moiety conferring the electrophilic character to its adjacentcarbonyl consisting of either X₁ or X₂ as previously defined genericallyin formula I.

Still for instructional purposes, the structural formula for the mostpreferred human leukocyte elastase inhibitor is ##STR11## the verticaldotted lines setting off each moiety constituting the specificarrangement for that particular peptidase inhibitor. Except for prolineand 2-indoline carboxylic acid the moieties encircled within the dottedlines represent the side chains of the α-amino acids (see pages 69-71 ofthe above cited Lehninger's text) or 1-naphthylmethyl.

Still another way of representing the foregoing substrate is by theformula ##STR12## with R, R₂, R₄ being the side chains of the particularα-amino acid, the amino acid of P₂ ' (P₂ primed) being the R₅, if any,of X₂ and the terminal P₃ ' being a specific of the Y radical of X₂, P₅being the terminal moiety sometimes referred to generically as (P_(n))and P₂ -P₃ -P₄ being the remaining α-amino acids of that R₁ moiety.

Still another, and the most convenient method for simply conveying thestructure involved is the formula ##STR13## wherein X consists of P₁'-P₂ 'Y when representative of ##STR14## wherein for the illustrationsabove, P₁ ' bears the --CH₃ side chain for R₄ and P₂ ' bears the R₅amino acid bearing the --CH₃ side chain and Y is NH₂, and P₁ -P₅ areshorthand designations for the depicted P₁ -P₅ moieties of the abovestructures II and III.

To expand on structure IV and (Ia) as it encompasses the scope of theother X moieties attached to the same P₁ -P₅ moieties, the followingseven structures are shown:

(a) MeOSuc-Ala-Ile-Pro-Val-CF₂ H (i.e., X₁ is --CF₂ H);

(b) MeOSuc-Ala-Ile-Pro-Val-CF₃ (i.e., X₁ is --CF₃);

(c) MeOSuc-Ala-Ile-Pro-Val-COOH (i.e., X₁ is --CO₂ R₃ with R₃ being H);

(d) MeOSuc-Ala-Ile-Pro-Val-CONH₂ (i.e., X₁ is --CONHR₃ with R₃ being H).

(e) ##STR15## (i.e., X₂ is ##STR16## with R₄ being the side chain ofalanine, R₅ ' and being the side chain of alanine and Y is NH₂ ;

(f) ##STR17## (i.e., X₂ is ##STR18## with R₅ being as defined in (e)above, and Y is NH₂ ; and (g) ##STR19## (i.e., X₂ is ##STR20## whereinR₅ is as defined in (e) above and Y is NH₂.

It is also convenient when defining the substrate compounds according tothe foregoing formula IV convention designation to define the ##STR21##moiety of X₂ as CF₂ -α-amino acid! wherein the name of the α-amino acidto which R₄ is a side chain is indicated such as, for example, thisconvention ##STR22## becomes CF₂ Ala!.

This will facilitate the writing and comprehension of the so-definedstructures.

In the definitions of the R₁ moieties of the following sub-genericformulae (i.e. Ia through Iv) it is to be understood that P_(g) is theoptional N-protecting group of the terminal α-amino acid. Thus, forexample, if the R₁ definition is P₂ P₃ P₄ P_(g) and P₃ and/or P₄ aredeleted, then the optional Group K protecting group would be on theterminal amine of the P₂ -α-amino acid.

Utilizing the foregoing illustrations those compounds of formula I whichare useful as inhibitors for human leukocyte elastase are represented bythe formula ##STR23## wherein R₂ is the side chain of the α-amino acidsof Groups E and G, with nor-valine and valine being preferred, with theproviso that when R₂ is a side chain of an α-amino acid of Group E andthe R₁ moiety bears a member of Group D in its P₂ position, then X isother than CF₃.

R₁ is -P₂ P₃ P₄ P_(g) with P₂ being selected from Groups D, E and F,with proline being preferred,

P₃ is selected from Groups D or E, with isoleucine being preferred,

P₄ is selected from Groups E or zero with alanine being preferred (whenP_(n) is zero then that particular moiety does not appear in thestructure, i.e. it is deleted,

P_(g) is selected from Group K with methoxysuccinyl being preferred,

X is any of the X₁ or X₂ moieties defined for formula I with R₅ being anα-amino acid of Groups E and G with alanine being preferred and Y isNH₂, and

R₄ is a side chain of an amino acid of Groups E and G with the sidechain of alanine preferred.

Human leukocyte elastase is released by polymorphonuclear leukocytes atsites of inflammation and thus is a contributing cause for a number ofdisease states. Thus the peptidase substrates of Formula (Ia) have ananti-inflammatory effect useful in the treatment of gout, rheumatoidarthritis and other inflammatory diseases, and in the treatment ofemphysema. In their end-use application the enzyme inhibitory propertiesof the compounds of (Ia) are readily ascertained by standard biochemicaltechnique well known in the art. Potential dose range for their end-useapplication will of course depend upon the nature and severity of thedisease state as determined by the attending diagnostician with therange of 0.01 to 10 mg/kg body per day being useful for theaforementioned disease states. The preferred compounds for this enzymeare:

MeOSuc-Ala-Ile-Pro-Val CF₂ -Ala!Ala-NH₂,

MeOSuc-Ala-Ile-Pro-Val-CF₃,

MeOSuc-Ala-Ile-Pro-Val-CO₂ Me,

MeOSuc-Ala-Ile-Pro-Val-CF₂ COOEt,

MeOSuc-Ala-Ile-Pro-Val-CHF₂,

MeOSuc-Ala-Ala-Pro-Val-CO₂ Me,

MeOSuc-Ala-Ala-Pro-Val- CF₂ -Ala!Ala-NH₂,

MeOSuc-Ala-Ala-Pro-Val-CF₃,

αN-(AdSO₂)!- N-(2-CBz)!-Lys-Pro-Val- CF₂ Ala!Ala-NH₂,

αN-(AdSO₂)!- N-(2-CBz)!-Lys-Pro-Val-CHF₂,

αN-(AdSO₂)!- N-(2-CBz)!-Lys-Pro-Val-CO₂ Me,

MeOSuc-Ala-Ile-Pro-Val-CO₂ Me, and

MeOSuc-Ala-Ile-Pro-Val-CO₂ H.

Those compounds of Formula I which are useful as inhibitors of CathepsinG are represented by the structural formula ##STR24## wherein X₁, X₂,R₃, R₄, R₅ and Y are as defined for human leukocyte elastase (FormulaIa),

R₁ is P₂ -P₃ -P₄ -P_(g) with P₂ being selected from Groups D, E, G or Kwith proline or benzoyl being preferred,

P₃ is selected from Groups E or G with alanine being preferred,

P₄ is selected from Groups E, G or is deleted with alanine beingpreferred,

P_(g) is selected from Group K with succinyl being preferred,

R₂ is a side chain of an amino acid of Groups E and F but preferably isthe Phe side chain, with the proviso that when R₂ is a side chain of anamino acid of Group E and the R₁ moiety bears a member of Group D in itsP₂ position, then X is other than CF₃.

The end-use application of the compounds (Ib) inhibiting Cathepsin G isthe same as for human leukocyte elastase inhibitors, includingarthritis, gout and emphysema, but also embracing the treatment ofglomerulonephritis and lung infestations caused by infections in thelung. For their end-use application, the potency and other biochemicalparameters of the enzyme inhibiting characteristics of the compounds of(Ib) is readily ascertained by standard biochemical techniques wellknown in the art. Actual dose ranges for their specific end-useapplication will, of course, depend upon the nature and severity of thedisease state of the patient or animal to be treated as determined bythe attending diagnostician. It is to be expected that the generalend-use application dose range will be about 0.01 to 10 mg per kg perday for an effective therapeutic effect. Preferred compounds of formulaIb are:

Suc-Ala-Ala-Pro-Phe-X₁, and specifically

Suc-Ala-Ala-Pro-Phe-CF₃,

Suc-Ala-Ala-Pro-Phe-COOH,

Suc-Ala-Ala-Pro-Phe-COOMe,

Suc-Ala-Ala-Pro-Phe-CF₂ H,

Suc-Ala-Ala-Pro-Phe CF₂ Ala!OH, and

Suc-Ala-Ala-Pro-Phe-CF₂ -COOEt.

Those compounds of Formula I which are useful as inhibitors of thrombinare represented by the formula ##STR25## wherein X is X₁ or X₂ asdefined in formula I with Y being OH, R₅ is preferably glycine or is amember of Group E or D or is zero,

R₄ is the side chain of an amino acid selected from Group C or G butpreferably is the glycine or serine side chain,

R₂ is preferably the arginine side chain but may also be a side chain ofan amino acid selected from Groups A and J,

R₁ is (a)-P₂ -P₃, (b)-P_(g) or (c)-P₂ -P₃ -P₄ -P_(g) with

(a) P₂ is selected from Groups D, E or F, preferably proline, P₃ isselected from Group F, each P₃ being in the D-configuration preferablyD-Phe,

(b) P_(g) is selected from Group K and is preferably dansyl or tosyl,

(c) P₂ is selected from Group E but preferably is alanine, P₃ isselected from Groups C, G and E but preferably is serine, P₄ is selectedfrom Groups F, G and E or is zero but preferably is Phe, P_(g) is anoptional Group K amino protecting group.

The compounds embraced by Formula (Ic) inhibit thrombin and therefore,as in the use of heparin, the compounds may be used as the initialanticoagulant agent in thrombophlebitis and coronary thrombosis. Fortheir end-use application, the potency and other biochemical parametersof the enzyme inhibiting characteristics of the compounds of (Ic) arereadily ascertained by standard biochemical techniques well known in theart. Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect. Preferred compounds are as expressed for Cathepsin Gand also include: ##STR26##

The compound of Formula I which are useful as inhibitors of chymotrypsinare represented by the structural formula ##STR27## wherein X₁, X₂, R₃,R₄, R₅ and Y are as defined for compounds of Ia, and R, is -P₂ -P₃ -P₄-P_(g) with,

P₂ being selected from Groups D, E, G,

P₃ is selected from Groups E or G or is zero with alanine beingpreferred,

P₄ is selected from Groups E or G or is deleted with alanine beingpreferred,

P_(g) is an optional Group K amino protecting group with succinyl andbenzoyl being preferred, and

R₂ is selected from a side chain of an amino acid of Groups E and F butpreferably is Phe or Tyr side chains, with the proviso that when R₂ is aside chain of an α-amino acid of Group E and the R, moiety bears amember of Group D in its P₂ position, then X is other than CF₃.

The end-use application of the compounds (Id) inhibiting chymotrypsin isin the treatment of pancreatitis. For their end-use application, thepotency and other biochemical parameters of the enzyme inhibitingcharacteristics of the compounds of (Id) is readily ascertained bystandard biochemical techniques well known in the art. Actual doseranges for their specific end-use application will, of course, dependupon the nature and severity of the disease state of the patient oranimal to be treated as determined by the attending diagnostician. It isto be expected that the general end-use application dose range will beabout 0.01 to 10 mg per kg per day for an effective therapeutic effect.Preferred compounds are as expressed for chymotrypsin G and alsoinclude:

Bz-Phe-CF₃,

Bz-Phe-COOH,

Bz-Phe-COOMe,

Bz-Tyr-CF₃,

Bz-Tyr-COOH,

Bz-Tyr-COOMe,

Bz-Phe-CHF₂,

Bz-Phe-CF₂ COOEt, and

Bz-Phe- CF₂ -Gly!Gly-OH.

The compounds of Formula I which are useful as inhibitors of trypsin arerepresented by the structural formula ##STR28## wherein X is X₁ or X₂ asdefined in formula I with Y being OH, R₅ is selected from Groups G, E orD or is zero but preferably is glycine,

R₄ is a side chain of an amino acid of Groups C or G but preferably isthe glycine or serine side chain,

R₂ is a side chain of an amino acid selected from Groups A or J butpreferably is the arginine side chain,

R₂ is selected from (a)-P₂ -P₃, (b)-P₂ or (C)-P₂ -P₃ -P₄ -P_(g) with

(a) P₂ is selected from Groups D, E or F but is preferably proline oralanine, P₃ is selected from Group F, (each being in the Dconfiguration) but preferably is (D)-Phe,

(b) P_(g) is selected from Group K but preferably is dansyl or tosyl,

(c) P₂ is selected from Group D or E but preferably is proline oralanine, P₃ is selected from Groups C, G and E but preferably is serine,P₄ is selected from Groups G and E or is zero but preferably is Phe. Pgof (a) and (c) are optional Group K amine protecting groups.

The end-use application of the compounds (Ie) inhibiting trypsin is inthe treatment of pancreatitis. For their end-use application, thepotency and other biochemical parameters of the enzyme inhibitingcharacteristics of the compounds of (Ie) is readily ascertained bystandard biochemical techniques well known in the art. Actual doseranges for their specific end-use application will, of course, dependupon the nature and severity of the disease state of the patient oranimal to be treated as determined by the attending diagnostician. It isto be expected that the general end-use application dose range will beabout 0.01 to 10 mg per kg per day for an effective therapeutic effect.The preferred compounds useful for inhibiting trypsin are the same asfor the inhibitors of thrombin.

The compounds of Formula I which are useful as inhibitors of plasmin arerepresented by the structural formula ##STR29## wherein X is X₁ or X₂,with CF₃, COOH, COOMe, and CF₂ COOEt being preferred,

R₁ is -P₂ -P₃ -P_(g) with P₂ being selected from Group F but preferablyis Phe, P₃ is selected from Groups B or F but preferably is Glu, andP_(g) is an optional Group K (preferably dansyl) amino protecting group,

R₂ is a side chain of an amino acid selected from Groups A and J butpreferably is the lysine side chain.

The compounds embraced by formula (If) inhibit plasmin and are thereforeantiproliferative agents useful in treating excessive cell growth,particularly in the treatment of benign prostatic hypertrophy andprostatic carcinoma, and in the treatment of psoriasis. For theirend-use application, the potency and other biochemical parameters of theenzyme inhibiting characteristics of the compounds of (If) is readilyascertained by standard biochemical techniques well known in the art.Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect. The preferred compounds are:

DNS-Glu-Phe-Lys-CHF₂,

DNS-Glu-Phe-Lys-COOH,

DNS-Glu-Phe-Lys-CF₃,

DNS-Glu-Phe-Lys-COOMe, and

DNS-Gly-Phe-Lys-CF₂ COOEt.

The compounds of Formula I which are useful as inhibitors of C₁-esterase are represented by the structural formula ##STR30## wherein Xis X₁ or X₂ with X₁ being preferred particularly when X₁ is CO₂ R₃ or--CF₃,

R₂ is a side chain of an amino acid selected from Groups A and J butpreferably is the Arg side chain,

R₁ is -P₂ -P_(g) with P₂ being selected from Groups E, G, D, C, F, A orB with Ala being preferred, and P_(g) is an optional Group K aminoprotecting group with CBZ being preferred,

R₄ is selected from the side chains of the amino acids of Group E, and

R₅ is selected from Group E and Y is preferably NH₂.

The compounds embraced by formula (Ig) inhibit C₁ -esterase and aretherefore useful in treating systemic lupus, arthritis, autoimmunehemolytic anemia and glomerulonephritis. For their end-use application,the potency and other biochemical parameters of the enzyme inhibitingcharacteristics of the compounds of (Ig) is readily ascertained bystandard biochemical techniques well known in the art. Actual doseranges for their specific end-use application will, of course, dependupon the nature and severity of the disease state of the patient oranimal to be treated as determined by the attending diagnostician. It isto be expected that the general end-use application dose range will beabout 0.01 to 10 mg per kg per day for an effective therapeutic effect.The preferred compounds are:

CBZ-Ala-Arg-CF₃,

CBZ-Ala-Arg-COOH,

CBZ-Ala-Arg-COOMe,

CBZ-Ala-(p-gua)*-Phe-CF₂ COOEt, and

CBZ-Ala-p-gua)*-Phe CF₂ Ala!NH₂.

gua is guanidino.

The compounds of Formula I which are useful as inhibitors of C₃-convertase are represented by the formula ##STR31## R₄ preferably beingthe alanine side chain, but is also a side chain of an amino acid ofGroup E,

R₅ is zero and Y is OR₃ (i.e., R₅ Y is OR₃),

R₂ is a side chain of an amino acid selected from Groups A or J, withthe Arg side chain being preferred,

R₁ is -P₂ -P₃ -P_(g) with P₂ being selected from Groups E or F, with Alabeing preferred,

P₃ is selected from Groups E or F with Leu being preferred, and

P_(g) is an optional Group K amino protecting group with Bz beingpreferred.

The compounds embraced by formula (Ih) inhibit C₃ -convertase and aretherefore useful in treating systemic lupus, arthritis, autoimmunehemolytic anemia and glomerulonephritis. For their end-use application,the potency and other biochemical parameters of the enzyme inhibitingcharacteristics of the compounds of (Ih) is readily ascertained bystandard biochemical techniques well known in the art. Actual doseranges for their specific end-use application will, of course, dependupon the nature and severity of the disease state of the patient oranimal to be treated as determined by the attending diagnostician. It isto be expected that the general end-use application dose range will beabout 0.01 to 10 mg per kg per day for an effective therapeutic effect.The preferred compounds are:

Bz-Leu-Ala-Arg-CF₃,

Bz-Leu-Ala-Arg-CHF₂,

Bz-Leu-Ala-Arg-CF₂ -COO-CH₂ Φ,

Bz-Leu-Ala-Arg CF₂ -Ala!OCH₂ Φ, and

Bz-Leu-Ala-Arg-COOCH₂ Φ.

The compounds of formula I which are useful as inhibitors of Urokinaseare represented by the formula ##STR32## wherein X is X₁ or X₂ with X₁being preferred and CO₂ R₃ and --CF₃ being most preferred,

R₄ is a side chain of an amino acid of Group E,

R₅ is selected from Group E, and

Y is NH₂,

R₁ is -P₂ -P₃ with P₂ being selected from Groups E and G with Ala andGly being preferred, and P₃ is selected from Group B with Glu beingpreferred,

R₂ is a side chain of an amino acid selected from Groups A and J withthe side chain of Arg being preferred.

Preferred Urokinase inhibitors are:

H-Glu-Gly-Arg-CF₂ H,

H-Glu-Gly-Arg-CF₃,

H-Glu-Gly-Arg-COOH,

H-Glu-Gly-Arg-CONH₂,

H-Glu-Gly-(p-gua)*Phe- CF₂ Ala!-Ala-NH₂, and

H-Gly-Gly(p-gua)*Phe-CF₂ CONH₂,

(p-gua) being para-guanidino

The compounds of formula (Ii) inhibit urokinase and therefore are usefulin treating excessive cell growth disease states. As such the compoundsare useful in the treatment of benign prostatic hypertrophy andprostatic carcinoma, the treatment of psoriasis, and in their use asabortifacients. For their end-use application, the potency and otherbiochemical parameters of the enzyme inhibiting characteristics of thecompounds of (Ii) are readily ascertained by standard biochemicaltechniques well known in the art. Actual dose ranges for their specificend-use application will, of course, depend upon the nature and severityof the disease state of the patient or animal to be treated asdetermined by the attending diagnostician. It is to be expected that thegeneral end-use application dose range will be about 0.01 to 10 mg perkg per day for an effective therapeutic effect.

The compounds of Formula I which are useful as inhibitors of plasminogenactivator are represented by the structural formula ##STR33## wherein Xis X₁ or X₂ with X₁ being preferred and --CF₃, COOH and COOMe being mostpreferred,

R₄ is a side chain of an amino acid of Group E,

R₅ is selected from Group E,

Y is NH₂ when X is X₂,

R₁ is -P₂ -P₃ -P_(g) wherein P₂ is Gly, P₃ is selected from Group B withGlu being preferred, and P_(g) is a Group K amino protecting grouppreferably dansyl, and

R₂ is a side chain of an amino acid selected from Groups A and J withArg being preferred.

Preferred compounds are:

DNS-Glu-Gly-Arg-COOMe,

DNS-Glu-Gly-Arg-CF₃,

DNS-Glu-Gly-Arg-COOH,

DNS-Glu-Gly-(p-gua)Phe-CHF₂,

DNS-Glu-Glu-(p-gua)Phe CF₂ Ala!AlaNH₂, and

DNS-Glu-Gly-(p-gua)PheCF₂ COOEt.

The compounds of the Formula (Ij) inhibit plasminogen activator andtherefore are useful in treating excessive cell growth disease statessuch, for example, being useful in the treatment of benign prostatichypertrophy and prostatic carcinoma, in the treatment of psoriasis andin their use as abortifacients. For their end-use application, thepotency and other biochemical parameters of the enzyme inhibitingcharacteristics of the compounds of (Ij) is readily ascertained bystandard biochemical techniques well known in the art. Actual doseranges for their specific end-use application will, of course, dependupon the nature and severity of the disease state of the patient oranimal to be treated as determined by the attending diagnostician. It isto be expected that the general end-use application dose range will beabout 0.01 to 10 mg per kg per day for an effective therapeutic effect.

The compounds of Formula I which are useful as inhibitors of acrosin arerepresented by the structural formula ##STR34## wherein X is X₁ or X₂,with X₁ being preferred, especially when X₁ is --CF₃, CHF₂, COOH orCOOMe. When X is X₂, R₄ is a side chain of an amino acid of Group E, R₅is Group E, or is deleted and Y is NH₂,

R₁ is -P₂ -P₃ -P_(g) with P₂ being selected from Group E with Leu beingpreferred, P₃ is selected from Group E with Leu being preferred, P_(g)is an optional Group K amino protecting group with Boc being preferred,and

R₂ is a side chain of an amino acid selected from Groups A and J withthe side chain of Arg being preferred. Preferred compounds are:

Boc-Leu-Leu-Arg-CF₂ H,

Boc-Leu-Leu-Arg-CF₃,

Boc-Leu-Leu-Arg-COOH,

Boc-Leu-Leu-(p-gua)Phe- CF₂ Ala!AlaNH₂, and

Boc-Leu-Leu-(p-gua)PheCF₂ CONH₂.

The compounds of formula (Ik) are acrosin inhibitors and therefore areuseful as anti-fertility agents in that they possess the characteristicsof preventing sperm from penetrating an otherwise fertilizable egg. Fortheir end-use application, the potency and other biochemical parametersof the enzyme inhibiting characteristics of the compounds of (Ik) arereadily ascertained by standard biochemical techniques well know in theart. Actual dose ranges for their specific end-use application will, ofcourse, depend upon the state of the patient or animal to be treated asdetermined by the attending diagnostician. It is to be expected that thegeneral end-use application dose range will be about 0.01 to 10 mg perkg per day for an effective therapeutic effect.

The compounds of Formula I which are useful as inhibitors of β-lactamaseare represented by the structural formula ##STR35## with the provisothat the depicted carbonyl moiety (attached to X) may exist in itschemically reduced form, i.e., ##STR36## with the reduced form beingpreferred, wherein X is X₁ or X₂ with --CF₃, COOH and COOMe being mostpreferred, and R₅ is deleted when X is X₂,

R₁ is P_(g), P_(g) being selected from Group K with COCH₂ Φ and Bz beingpreferred,

R₂ is a side chain of an amino acid selected from Group E, G and C withthe side chain of glycine being preferred. The preferred compounds are:

ΦCH₂ COHNCH₂ COCF₃,

ΦCH₂ COHNCH₂ COCOOH,

ΦCH₂ COHNCH₂ COCOOMe,

ΦCH₂ COHNCH₂ CHOHCF₃,

ΦCH₂ COHNCH₂ CHOHCOOH,

ΦCH₂ COHNCH₂ CHOHCOOMe,

ΦCH₂ COHNCH₂ COCHF₂, and

ΦCH₂ COHNCH₂ CHOHCF₂ COOEt.

The compounds embraced by formula (Il) inhibit β-Lactamase and thereforeare useful in the potentiation of antibacterial agents, particularly theβ-lactam anti-bacterials. For their end-use application, the potency andother biochemical parameters of the enzyme inhibiting characteristics ofthe compounds of (Il) are readily ascertained by standard biochemicaltechniques well known in the art. Actual dose ranges for their specificend-use application will, of course, depend upon the nature and severityof the disease state of the patient or animal to be treated asdetermined by the attending diagnostician. It is to be expected that thegeneral end-use application dose range will be about 0.01 to 10 mg perkg per day for an effective therapeutic effect.

The compounds of Formula I which are useful as inhibitors of D-Ala-D-AlaCarboxypeptidase ##STR37## wherein X is X₁ or X₂, R₄ is the side chainof D-ala, R₅ is deleted and Y is OH or OR₃,

R₂ is the side chain of D-ala,

R₁ is P₂ -P_(g) with P₂ being (Nα,ε)-di-Ac-Lys or Groups E and C with(Nα,ε)-di-Ac-Lys being preferred, P_(g) is an optional Group K aminoprotecting group with Ac being preferred.

The preferred compounds are:

(Nα,ε)-di-Ac-Lys-D-Ala CF₂ -(D)-Ala!OH,

(Nα,ε)-di-Ac-Lys-D-Ala CF₂ -D-Ala!OMe

(Nα,ε)-di-Ac-Lys-D-Ala-CHF₂,

(Nα,ε)-di-Ac-Lys,D-Ala-CF₂ COOEt, and

(Nα,ε)-di-Ac-Lys-D-AlaCF₃.

The compounds embraced by formula (Im) are antibacterial agentsparticularly useful against gram negative organisms. For their end-useapplication, the potency and other biochemical parameters of the enzymeinhibiting characteristics of the compounds of (Im) is readilyascertained by standard biochemical techniques well known in the art.Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect.

The compounds of Formula I which are useful as inhibitors of Cathepsin Bare represented by the structural formula ##STR38## wherein X is X₁ orX₂ with X₁ being preferred and CF₃ and COOH being particularly preferredand when X is X₂, R₄ is a side chain selected from the amino acids ofGroup E with the side chain of Leu being preferred,

R₅ is selected from Groups G, E or F with Gly being preferred and Y isOH,

R₁ generically is (a)-P₂ -P_(g) or (b)-P₂ -P₃ -P_(g) wherein for

(a) P₂ is selected from Groups E and F with Phe being preferred andP_(g) is selected from Group K with CBZ being preferred, and

(b) P₂ is selected from Groups E and F with Leu being preferred, -P₃being selected from groups E and F with Leu being preferred and P_(g) isselected from Group K with Ac being preferred,

R₂ is a side chain of an amino acid selected from Group A and J orThrCOCH₂ Φ, with the side chain of Arg being preferred. The preferredcompounds are: ##STR39##

The compounds of formula (In) inhibit Cathepsin B and therefore areuseful in treating excessive cell growth disease states such as, forexample, being useful in treating benign prostate hypertrophy, prostaticcarcinoma, in treating psoriasis and in their use as abortifacients. Fortheir end-use application, the potency and other chemical parameters ofthe enzyme inhibiting characteristics of the compounds of (In) isreadily ascertained by standard biochemical techniques well known in theart. Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect.

The compounds of Formula I which are useful as inhibitors of renin arerepresentative by the structural formula ##STR40## with the proviso thatthe depicted carbonyl moiety attached to X may exist in its chemicallyreduced form, i.e., ##STR41## wherein X is X₁ or X₂, which when X is X₁,CF₃, COOH or COOMe are preferred and when X is X₂,

R₄ is a side chain of an amino acid selected from Groups E, F or G withthe side chain of Val being preferred,

R₅ is P₂ '-P₃ '-P₄ ', P₂ ' being from Groups E, F or is deleted, with P₃' being selected from Groups E or F or is deleted with Ile beingpreferred and P₄ ' being selected from Groups E, C or F or is deletedwith His being preferred and Y is OH or NH₂,

R₂ is a side chain of an amino acid selected from Groups E or F or iscyclohexylmethylene with Leu being preferred,

R₁ is -P₂ -P₃ -P₄ -P₅ -P_(g) wherein P₂ is selected from Groups E, C orF with His being preferred, P₃ is selected from Groups E or F with Phebeing preferred, P₄ is selected from Groups E, D, F or is deleted withPro being preferred, P₅ is selected from Groups E, C, F or is deletedwith His being preferred, and P_(g) is selected from Group K with MeOSucbeing preferred. The preferred compounds are:

CBZ-Nal(l)-His-Leu-CHF₂,

CBZ-Nal(l)-His-Leu-CF₃,

CBZ-Nal(l)-His-Leu-CF₂ -COOEt ,

MeOSuc-His-Pro-Phe-His-Leu- CF₂ -Val!Ile-His-OH,

MeOSuc-Pro-Phe-His-Leu- CF₂ -Val!Ile-His-OH,

MeOSuc-His-Phe-His-Leu- CF₂ -Val!Ile-His-OH,

MeOSuc-His-Pro-Phe-His-Leu- CF₂ -Val!Ile-OH,

MeOSuc-His-Pro-Phe-His-Leu- CF₂ -Val!His-OH,

BOC-His-Pro-Phe-His-Leu CF₂ -Val!-Ile-His-OH,

BOC-His-Pro-Phe-His-Leu- CF₂ -CO!-Ile-His-NH₂, and

BOC-Pro-Phe-His-Leu CF₂ -Val!-Ile-His-NH₂.

The compounds of Formula (Io) inhibit renin and therefore are used asantihypertensive agents useful in treating hypertension. For theirend-use application, the potency and other biochemical parameters of theenzyme inhibiting characteristics of the compounds of (Io) are readilyascertained by standard biochemical techniques well known in the art.Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect.

The compounds of Formula I which are useful as inhibitors of pepsin arerepresented by the structural formula ##STR42## with the proviso thatthe depicted carbonyl moiety attached to X may exist in its chemicallyreduced form, i.e., ##STR43## wherein X is X₁ and X₂, which when X is X₁--CF₂ H, CF₃ and CONH₂ are preferred, and when X is X₂ then,

R₄ is a side chain of an amino acid selected from the Groups E, G and Fwith the side chain of Gly being preferred,

R₅ is selected from Groups E and F with Ala being preferred and Y is--NHCH₂ CH(CH₃)₂ or --NHCH₂ CH₂ CH(CH₃)₂,

R is -P₂ -P₃ -P_(g) with P₂ being selected from Groups E or F with Valbeing preferred, P₃ is selected from Groups E or F with Val beingpreferred or is deleted and P_(g) is selected from Group K preferablyIva, and

R₂ is a side chain of an amino acid selected from Groups E and F withthe side chain of Leu being preferred.

The preferred compounds are: ##STR44##

The compounds of the formula (Ip) inhibit pepsin and therefore exert anantiulcer effect useful in the treatment and prevention of ulcers. Fortheir end-use application, the potency and other biochemical parametersof the enzyme inhibiting characteristics of the compounds of (Ip) arereadily ascertained by standard biochemical techniques well known in theart. Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect.

The compounds of formula I which are useful as inhibitors of Cathepsin Dare represented by the structural formula ##STR45## wherein X is X₁ orX₂ which when X is X₁, the preferred groups are --CO₂ R₃ or --CF₃, andwhen X is X₂,

R₄ is a side chain of an amino acid selected from Groups E and F withthe side chain of Phe being preferred,

R₅ is selected from Groups E and F with Ala being preferred,

Y is --NH(CH₂)₂ CH(CH₃)₂ or --NHCH₂ CH(CH₃)₂,

R is -P₂ -P₃ -P_(g) with P₂ being selected from Groups E and F, with Valbeing preferred, P₃ is selected from Groups E and F with Val beingpreferred, and P_(g) is selected from Group K with CBZ eing preferred,and

R₂ is a side chain of an amino acid selected from Groups E and F, withthe side chain of Phe being preferred.

The preferred compounds are:

CBZ-Val-Val-Phe-CF₂ -CO-Ala-Iaa,

CBZ-Val-Val-Phe-CF₂ H,

CBZ-Val-Val-Phe-CF₃,

CBZ-Val-Val-Phe CF₂ -Phe!Ala-NH(CH₂)₂ CH(CH₃)₂,

CBZ-Val-Val-Phe CF₂ -Phe!Ala-NHCH₂ CH(CH₃)₂, and with Iaa being isoamylamide.

As inhibitors of Cathepsin D the compounds of formula (Iq) are usefulfor the same end-use applications set forth for human leukocyte elastaseinhibitors (Ia) and are also useful as antidemyelinating agents usefulto prevent and arrest nerve tissue damage. For their end-useapplication, the potency and other biochemical parameters of the enzymeinhibiting characteristics of the compounds of (In) are readilyascertained by standard biochemical techniques well known in the art.Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect.

The compounds of formula I which are useful as inhibitors of angiotensinconverting enzyme (ACE) are represented by the structural formula##STR46## wherein X is only X₂ wherein, R₄ is a side chain of an aminoacid selected from Groups E or G with the side chain of Gly beingpreferred,

R₅ is selected from Groups A, B, C, D, E, F and G with Group D beingpreferred and Y is OH,

R₁ is selected from Group K with Bz being preferred,

R₂ is a side chain of an amino acid selected from Group E, F and G withthe side chain of Phe being preferred. The preferred species areillustrated as ##STR47## with Φ being phenyl. This preferred compound isalso shown as Bz-Phe CF₂ -Gly!Ind-OH.

Other preferred compounds are:

Bz-Phe CF₂ -Gly!Pro-OH and

Bz-Phe-CF₂ -CO-Pro-OH.

The compounds of formula (Ir) inhibit ACE and are therefore useful asantihypertensives useful in treating hypertension. For their end-useapplication, the potency and other biochemical parameters of the enzymeinhibiting characteristics of the compounds of (Ir) are readilyascertained by standard biochemical techniques well known in the art.Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect.

The compounds of Formula I which are useful as inhibitors ofenkephalinase are represented by the structural formula ##STR48##wherein X represents X₂ wherein, R₄ is a side chain of an amino acidselected from Group E or F with the side chain of Phe being preferred,

R₅ is selected from the Groups E or F or zero with the proviso that whenR₅ is zero, Y is NH₂, with Met being preferred and Y is NH₂ or OH,preferably OH when R₅ is Met or other α-amino acid,

R₁ generically is -P₂ -P₃, with P₂ being Gly and P₃ being selected fromGroup F or is deleted with Tyr being preferred, and

R₂ is the side chain of Gly.

The preferred compounds are:

H-Tyr-Gly-Gly-CF₂ -CO-Phe-Leu-OH,

H-Tyr-Gly-Gly CF₂ -Phe!Met-OH,

H-Tyr-Gly-Gly CF₂ -Phe!LeuNH₂, and

H-Tyr-Gly-Gly-CF₂ -CO-Leu-OH.

The compounds of formula (Is) inhibit enkephalinase and therefore areuseful as analgesics. For their end-use application, the potency andother biochemical parameters of the enzyme inhibiting characteristics ofthe compounds of (Is) are readily ascertained by standard biochemicaltechniques well known in the art. Actual dose ranges for their specificend-use application will, of course, depend upon the nature and severityof the disease state of the patient or animal to be treated asdetermined by the attending diagnostician. It is to be expected that thegeneral end-use application dose range will be about 0.01 to 10 mg perkg per day for an effective therapeutic effect.

The compounds of Formula I which are useful as inhibitors of pseudomonaselastase are represented by the structural formula ##STR49## wherein Xis X₂ with, R₄ being a side chain of an amino acid selected from GroupsE and F with the side chain of Ile being preferred,

R₅ is selected from Groups E and G with Ala being preferred and Y isNH₂,

R₁ is -P₂ -P_(g) with P₂ being selected from Group E with Ala beingpreferred, P_(g) is selected from Group K with MeOSuc being preferred,

R₂ is a side chain of an amino acid selected from Groups E and G withthe side chain of Ala being preferred.

The preferred compounds are:

MeOSuc-Ala-Ala CF₂ -Ile!Ala-NH₂ and

MeOSuc-Ala-Ala-CF₂ -CO-Ile-Ala-NH₂.

The compounds of the Formula (It) inhibit Pseudomonas elastase andtherefore are useful as antibacterial agents particularly useful againstinfections caused by pseudomonas bacteria. For their end-useapplication, the potency and other biochemical parameters of the enzymeinhibiting characteristics of the compounds of (It) are readilyascertained by standard biochemical techniques well known in the art.Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect.

The compounds of formula I which are useful as inhibitors of leucineaminopeptidase are represented by the formula ##STR50## wherein Xembraces all of X₁ and X₂ which when X is X₁, CO₂ R₃ or --CF₃ arepreferred and when X is X₂,

R₄ is the side chain of an amino acid selected from any Group except Kwith the side chain of Ala and Group E being preferred,

R₅ is any Group except K with Ala and Group E being preferred,

Y is NH₂,

R₁ is hydrogen, and

R₂ is a side chain of an amino acid selected from Groups A, B, E, F andJ with the side chains of Phe, Leu, Glu, and Arg being preferred. Thepreferred compounds are:

H-Leu-CHF₂,

H-Leu-CF₂ -COOEt,

H-Arg-CF₃,

H-(p-gua)Phe-CF₃,

H-Leu-CF₃ and H-Leu-COOH,

H-Leu CF₂ -Ala!Ala-NH₂ and H-Leu-COOMe or Leu-COOH, and

H-Arg-CO-CF₂ -Phe-OH.

The compounds of formula (Iu) are inhibitors of leucine amino peptidaseand therefore are useful as immunostimulants useful in conjunctivetherapy in the treatment with other known anticancer agents. For theirend-use application, the potency and other biochemical parameters of theenzyme inhibiting characteristics of the compounds of (Iu) are readilyascertained by standard biochemical techniques well known in the art.Actual dose ranges for their specific end-use application will, ofcourse, depend upon the nature and severity of the disease state of thepatient or animal to be treated as determined by the attendingdiagnostician. It is to be expected that the general end-use applicationdose range will be about 0.01 to 10 mg per kg per day for an effectivetherapeutic effect.

The compounds of Formula I which are useful asinhibitors of kallikreins,tissue or plasma, are represented by the formula ##STR51## wherein X isX₁, R₂ preferably is the side chain of Arg,

R₁ is a peptide -P₂ -P₃ with

P₂ being selected from the Groups F and E with Phe being preferred,

P₃ being selected from Groups C, E or F, the residues of which may be ineither the D- or L-configuration.

The preferred compounds of this formula (Iv) are:

D-Pro-Phe-Arg-CF₂ H,

D-Pro-Phe-Arg-CF₃,

D-Pro-Phe-Arg-CO₂ H, and

D-Pro-Phe-Arg-CONH₂.

The compounds of formula (Iv) are inhibitors of the kallikreins, tissueor plasma, and therefore inhibit kinin formations. Kinins, generallyknown to induce pain and vascular permeability associated withinflammation and infection, e.g., bacterial and viral, the inhibition ofthe kinin formation renders these compounds useful in the alleviation ofpain and inflammation. Furthermore, these compounds are useful as malecontraceptives in that they will dramatically interfere with normalsperm function. In their end-use application dose range will be about0.01 to 10 mg per keg per day for an effective therapeutic effect.

Having defined the scope of compounds embraced within the genericformula I and within the individual subgeneric groups of each of the 21enzymes, the manner in which such compounds may be prepared willhereinbelow be described as illustrated. The preparation of thecompounds of formula I may be achieved using standard chemical reactionsanalogously known to be useful for the preparation of a variety of knownpeptides. Indeed, for the most part, once certain key intermediateα-amino acid derivatives are prepared, the procedures for obtaining thefinal products may readily be effected using standard techniques knownto those skilled in the field of peptide chemistry. For this purpose, ahandy reference text for these techniques is the 1985 "The Practice ofPeptide Synthesis" by M. Bodanszky and A. Bodanszky, wherein theparameters and techniques affecting the selection, use and removal ofprotective groups for individual and groups of amino acids is detailed,and which also contains activation and coupling techniques and otherspecial procedures. However, before the application of these peptidechemistry techniques may be applied, certain key intermediatescontaining the activated electrophilic ketone moiety must first beprepared. The preparation of the key intermediates is described asfollows.

For those compounds wherein X₁ represents either --CF₂ H or --CF₃, thekey intermediates required for the application of the standard peptidecoupling techniques are compounds of formula IIIa-b ##STR52## wherein X₁' is --CF₃ or --CF₂ H, and R₂ is as previously defined in formula I.Similarly, designations R₁, R₂, R₃, R₄, R₅ and Y shown in the followingreaction schemes A through D are as defined in formula I, except thatany subgeneric or other modifications thereof (as in X₁ ') arehighlighted by the use of a primed symbol with a specific designationfor such modified symbol. The preparation and application of thesecompounds is depicted by Reaction Scheme A. ##STR53## wherein R₆ isalkyl, phenyl or other equivalent moiety, and X₁ ' is --CF₂ H or --CF₃.

In general, the formation of the substituted azlactones (VI) is effectedfrom the N-protected amino acids (V) by standard reaction conditionswherein the amino acid derivative (V) is heated in the presence of anacid anhydride. The so-produced azlactone (VI) is reacted with a di- ortrifluoroacetic acid anhydride or acid halide to give a fluorinatedintermediate which (with or without isolation) is treated with anhydrousoxalic acid to produce the N-protected fluorinated ketone (VII)whereupon the ketone is chemically reduced to its alcoholic amide (VIII)is cleaved under standard acidic conditions to yield its amide acid salt(e.g., its hydrochloride (IX)). After neutralization, the alcohols(IIIa) may be coupled to R₁ using standard peptide chemistry techniquesto produce compounds (X) which are subjected to the Swern oxidationprocedure to obtain the desired products XIa and XIb (the ketone orhydrate respectively). Alternatively, the alcohols (IIIa) may beoxidized to the ketones (IIIb) which are coupled to R₁ according tostandard peptide chemistry techniques. When employing this alternativeroute, the amino moiety is first protected with a Boc protecting group,the OH function oxidized to its ketone via Swern oxidation procedures,and then the Boc protecting group removed and the resulting compounds(IIIb) are then coupled to R₁.

In effecting the foregoing reactions, standard and well-known techniquesanalogously known are utilized, for example, the azlactones (VI) arechemically transformed to their di- or trifluoromethyl derivatives(their X₁ ' derivatives) (VII) by heating the azlactone and thefluoroacetic acid anhydride or acid halide reactants at temperatures ofabout 30° to 200° C. for about 1-24 hours (although under very mildconditions it may take up to one week) preferably using molar equivalentquantities of the reactants. In the event excess quantities of theanhydride reactant is used, such excess should be removed before thenext step and the crude product is treated with anhydrous oxalic acid.The fluorinated ketone is reduced to its alcohol using excess quantitiesof sodium borohydride or any other suitable reducing agent, e.g., sodiumcyanoborohydride. Following reduction, the reaction is quenched and theamide is cleaved understandard acidic conditions in water, alcohol orother hydroxylic solvent. The solution is made basic and extracted toobtain the corresponding alcohol (IIIa).

It is, of course, obvious to one of ordinary skill in the art that theconditions of the steps of Reaction Scheme A may have an impact on theR₂ side chain and thus procedures will have to be taken to protect thoseR₂ moieties which are not compatible with the various reactionconditions. For example, R₂ moieties which belong to Group E aregenerally compatible. Similarly, R₂ side chain radicals from Groups F,J, and G are compatible. Radicals of Group A need protection. Sincearginine may be considered as a derivative of ornithine, the ornithinederivative may first be prepared and then converted to the arginine sidechain otherwise the guanidino function of the arginine moiety will haveto be protected. The Group C radicals of serine, threonine and cysteinemust be protected, preferably with an ether (e.g., benzyl ether).Preferably, the --OH and --SH functions of these groups are protectedbefore the azlactone is formed. The (X) intermediate wherein X₁ ' is--CF₃ and R₂ is H is known (Journal of the American Chemical Society,70, 143 (1948)), and thus the CF₂ H analogs may be prepared using theanalogous procedures. The carboxyl moiety of the Group B R₂ side chainsmust also be protected. The need for the selection of the protectinggroups and the reaction conditions for compatability, selective cleavageand other factors obvious to those skilled in the art are well known andappreciated by those skilled in this field of chemistry.

For those compounds wherein X₁ represents CO₂ R₃, CONR₃ or COR₅ Y, thekey intermediates required for the application of the standard peptidecoupling techniques have the formula ##STR54## with R₃ ' being aspreviously defined for R₃ except that H is omitted from its definition.

The preparation and application of these compounds may be depicted bythe following reaction scheme. (NB. The desired stereochemistry at theN-substituted carbon is obtained unless otherwise noted.) ##STR55##wherein A.sup.⊖ is the anion of the acid employed and R₃ ', except forthe exclusion of H, is as defined for R₃, and P_(g) is a suitable aminomoiety protecting group, and in XXV of reaction (b) R¹ is the same as##STR56## and R₅ ' is other than zero.

Compounds XIII are generally known starting materials. (In general, suchmaterials may be prepared by converting the appropriate L-amino acid toits ester, preferably its methyl ester by standard esterificationprocedures (e.g., SOCl₂ in the presence of alcohol), the ester isN-protected, preferably with di-t-butyl dicarbonate (Boc). Theso-protected R₂ -amino acid is chemically reduced to the desiredaldehydic form (XIII) of the N-protected amino acid, preferably withdiisobutylaluminum hydride (Dibal); all such procedures being bytechniques well known in the art. Of course, other procedures forobtaining the same end products are readily available by techniques wellknown in the art.

The reaction steps of Reaction Scheme B also use standard and well knowntechniques. For example, conversion of the aldehydes (XIII) to thecorresponding cyanohydrin is effected by reaction with a bisulfite(e.g., NaHSO₃) to obtain a bisulfite addition product XIV which istreated with a metallocyanide (e.g., KCN) to produce the correspondingcyanohydrin (XV). Of course, other procedures are readily available forthe conversion of the aldehyde to the cyanohydrin derivatives (XV). Thecyanohydrins are heated in a mixture of an aqueous acid and watermiscible solvent such as an ether (preferably dioxane) to form thedesired hydroxy acid (XVI) as a mixture of its diastereoisomers. Thesecompounds are subjected to neutralization and purification by standardprocedures, such as ion exchange resin chromatographic techniques, toyield products which are esterified to obtain the desired keyintermediates (XII).

In effecting B(a), the amino esters (XII) are coupled with the R₁ moietyaccording to standard peptide coupling techniques, taking care that theprotective group utilized (if any) are selectively cleavable over theCO₂ R₃ ' moiety. Oxidation of the coupled products is best achieved withthe Swern reaction to convert the alcohol to its keto form which, asnoted above, can exist in equilibrium with its hydrate.

In effecting B(b), the ester (XVII) is treated with an amine (R₃ NH₂) togive the amide (XIX) which may be oxidized via the Swern oxidationprocedures to its keto amide (XX). In this instance oxidation conditionsother than that of the Swern conditions may also be employed (e.g.,oxidation with pyridinium dichromate).

In effecting B(c), the keto ester (XVIII) is treated with a base (e.g.,LiOH) to give its keto acid (XXI) except in the case when R₁ contains aterminal methoxysuccinyl moiety in which case the R₃ ' must beselectively cleavable, e.g., R₃ ' ought to be t-butyl or benzyl whichare selectively cleaved under acidic or hydrogenolysis conditionsrespectively. In effecting step B(d) the keto acid (XXI) is converted toits amide by standard coupling procedures.

In effecting B(e), the acid is coupled with R₅ Y according to standardprocedures, taking care to protect and deprotect as needed in the lightof the various groups in the definition of R₅ and Y. In reaction B(f)the ester (XVII) is converted to an amide and the amide oxidyzedaccording to Swern oxidation conditions.

As noted above (following the discussion of Reaction Scheme A), theconditions of the foregoing reactions in the obtention of the desiredintermediates and final products of Reaction Scheme B are effectedtaking care that the R₂ -side chain radicals are compatible. AlthoughGroups E, F and G are generally compatible, protection of some R₂ sidechains will be necessary. For example, histidine will have to beprotected, while tyrosine and tryptophan ought be protected in order toimprove overall yields. Again, ornithine must have its terminal deltaamino group protected and ornithine may be converted to arginine. Aprotecting group would also be needed on a guanidino group. All aminoaids, e.g., cysteine and threonine having reactive groups in their sidechain preferably are protected.

In the preparation of those compounds wherein X₂ is ##STR57## theintermediates will be those compounds of the formulae ##STR58## whichcompounds may be prepared and applied according to Reaction Scheme C.##STR59##

The azlactone (VI) is prepared as in Reaction Scheme A and the stepsgoing from VI to XXV are analogous to those of that Scheme except thatthe azlactone is treated with an unsaturated fluorinated carboxylic acidanhydride, and the product is treated with anhydrous oxalic acid toproduce compounds XXV. Utilizing these intermediates (XXV) severalpathways may be utilized to obtain the desired products. In one pathway(C-1) the intermediate is sequentially subjected to a) a chemicalreduction of the electrophilic ketone, and b) hydrolysis of the amide bystandard procedures prior to coupling the R₁ moiety. The coupling isreadily accomplished using standard peptide chemistry couplingprocedures (already referenced) to produce compounds of formula XXVIthese intermediates are also available for alternate pathways, i.e.,C-1a or C-1b. In pathway C-1a the intermediates are sequentially treatedwith (a) ozone according to standard ozonolysis procedures to producethe corresponding ozonide, (b) treatment with dimethylsulfide to convertthe ozonide to its aldehydic form and (c) oxidation, preferably usingthe Jones oxidation procedure to produce compounds of formula XXIVa.These compounds (XXIVa) are sequentially subjected to (a) R₅ Y couplingand (b) Swern oxidation reactions according to already describedstandard procedures. In those instances wherein it is desired to firstprotect the hydroxy group, pathway C-1b is available. This pathwayessentially mimics C-1a except that the hydroxy function is protectedprior to ozonolysis and the hydroxy protecting group (i.e., R₇) isremoved in preparation for the Swern oxidation reaction. Typicalprotecting groups compatible with the described reactions can be used.Preferably the methoxyethoxymethyl group is utilized and is readilyremoved prior to the Swern oxidation by standard techniques such as bytreatment with Zn Br₂.

In pathway C-2 the intermediates are directed subjected to the abovedescribed sequential reactions (ozonolysis, treatment with DMS, andoxidation) to produce compounds of formula XXIX which in preparation forR₅ Y coupling are converted to the spiro lactones of formula XXX.Coupling, and deprotection (if necessary) produce the desired compoundsXXXI using standard techniques.

Pathway C-3, a variation of pathway C-1b, first reduces theelectrophilic ketone to a hydroxy function which is protected with asuitable protecting group (e.g., methoxyethoxymethyl) and the resultingcompounds XXVI and subjected to (a) ozonolysis, treatment with DMS, andthe Jones oxidations, (b) R5Y coupling and deprotection reactions, and(c) Swern oxidation, (all of these reactions being done according to theabove described procedures for these reactions) to produce the desiredcompounds of formula XXXI.

In those instances wherein difluorinated acid anhydrides are requiredfor the preparation of the fluoro-methyl azlactones, such anhydrides maybe prepared by reacting tetrafluoroethylene (F₂ C:CF₂) with an R₄CH═CHCH₂ OH reactant in the presence of a base (e.g., NaH) and theso-desired R₄ CH═CHCH₂ OCF₂ --CF₂ H intermediate is treated withbutyllithium to produce an acid fluoride ##STR60## which is converted toits anhydride by standard procedures. Here again, it is obvious thatcompatibility features must be facilitated to ensure that the relevantgroups can withstand the butyllithium reaction; thus the R₄ moiety hasto be protected when incompatible with the butyllithium reaction.

For those compounds wherein X₂ represents ##STR61## the keyintermediates useful for the preparation of the compounds of formula Ibearing this group will be of the formulae ##STR62## the preparation andapplication of which is depicted by reaction Scheme D. ##STR63## whereinP_(g) ' is a protecting group suitably stable to the reaction stepsinvolved and which is selectively cleaved following R₅ Y coupling andthe initial alkylation of XXXIV. R₅ 'Y is as defined for R₅ Y exceptthat it optionally contains a protecting group.

Following the initial step of alkylating the N-protected aldehyde offormula XXXIV with an appropriate halide in the presence of zinc, thesteps following the obtention of compounds XXXV follow the analogousprocedures already described for Reaction Schemes A-C.

Having generally described the procedures by which the compounds of thisinvention may be prepared, the following specific examples serve tofurther illustrate the standard techniques and procedures which may beutilized to prepare the enzyme inhibitors of this invention (I).

EXAMPLE 1 N^(l) -(2-Hydroxy-3,3-difluoro-1-isobutyl-5-hexenyl)-N²-isovaleryl valinamide

To a solution of 0.621 g (3 mmol) of6-amino-4,4-difluoro-8-methyl-1-nonen-5-ol (obtained from thecorresponding HCl salt by treatment of aqueous solution with 4N NaOH andextracted with Et₂ O) and 0.603 g (3 mmol) of N-isovaleryl valine in 30ml THF at 0° C. was added 0.62 g of dicyclohexyl carbodiimide. Themixture was stirred for 15 hours at 25° C., filtered and the filtrateconcentrated to yield a semisolid which was dissolved in CH₂ Cl₂. Theorganic layer was washed with 1N HCl aqueous KHCO₃ and then brine, dried(MgSO₄) and flash evaporated to afford a solid, which was purifiedfurther by chromatography in SiO₂ (CHCl₃ /Et₂ O (2:1)). The productcontaining fractions were combined, flash evaporated to give the desiredproduct. Rf 0.15 (CHCl₃ /Et₂ O) (2:1)).

EXAMPLE 2 3-Phenacetylamino-1,1,1-trifluoro-2-propanol

To a mixture of 1.3 g of 3-amino-1,1,1-trifluoro-2-propanol HCl and 1.62g of triethylamine in 26 ml of THF at 0° C. under nitrogen was addeddropwise a solution of 1.27 g of phenacetylchloride in 5 ml THF. Thereaction mixture was allowed to warm to 25° C. and then stirred for 1hour. The mixture was diluted with CH₂ Cl₂ and washed with H₂ O, twicewith 0.1N HCl, and then brine. After drying (MgSO₄), the solvent wasflash evaporated and the residue (1.8 g) recrystallized from CH₂ Cl₂ toyield 1.4 g of product; m.p. 96° C.

EXAMPLE 3 N¹ -(2-Hydroxy-3,3,3-trifluoro-1-isopropylpropyl) N²-phenylmethyloxycarbonyl-prolinamide

To a mixture of 1.1 g of N-phenylmethyloxycarbonyl proline TDO-ester (CfHollitzer, Seewald and Steglichm Ang.Int. Edit. 1976, Vol. 15, 444) and0.42 g of 3-amino-1,1,1-trifluoro-4-methyl-2-pentanol hydrochloride in50 ml of CH₂ Cl₂ was added dropwise 0.40 g of triethylamine. Afterstirring for 14 hours at 25° C., aqueous KHSO₄ was added, the layersseparated and the organic layer washed with aqueous KHSO₄, aqueousKHCO₃, H₂ O and then brine (2×). After drying (MgSO₄), solvents wereflash evaporated to yield 0.54 g of a solid residue which wasrecrystallized in Et₂ O to give 0.24 g of the analytically pure expectedamide; m.p. 99° C.

EXAMPLE 43-tert-Butyloxycarbonylamino-1,1,1-trifluoro-5-methyl-2-hexanol

A mixture of 0.5 g of 3-amino-1,1,1-trifluoro-5-methyl-2-hexanol HCl,0.5 g of di-tert-butyl dicarbonate and 0.45 g of KHCO₃ in 1.6 ml in 1.6ol of H₂ O/dioxane (1:1) was stirred at room temperature for 14 hours.Workup in Et₂ O/H₂ O gave, after washing of the organic layer withaqueous NaHSO₄, H₂ O and brine and drying (MgSO₄) followed by flashevaporation of the solvents 0.55 g of the expected Boc derivative, Rf0.44 (Et₂ O/pentane (1:1)).

EXAMPLE 5 3-Phenacetylamino-1,1,1-trifluoro-2-propanone

To a solution of 0.84 g of oxalyl chloride in 5 ml of CH₂ Cl₂ at -55° C.(inside temperature) was added 1.03 g of dimethylsulfoxide in 1 ml ofCH₂ Cl₂. After 5 minutes at -55° C., 1.0 g of3-phenacetylamino-1,1,1-trifluoro-2-propanol in 5 ml CH₂ Cl₂ and 0.2 mlof DMSO were added. The mixture was stirred for 15 minutes at -55° C.and then triethylamine was added to adjust the pH to 7.0. The mixturewas allowed to warm to 250° C., diluted further with CH₂ Cl₂ and washedwith H₂ O and then 1N HCl. The organic layer was dried (MgSO₄), flashevaporated to yield the amide ketone, which was purified further bychromatography on SiO₂ (CHCl₃ /Et₂ O (2:1)). Rf 0.29. The productcontaining fractions were combined and solvent was evaporated underreduced pressure to yield the desired product as a mixture of ketone andhydrate.

EXAMPLE 63-tert-Butyloxycarbonylamino-1,1,1-trifluoro-5-methyl-2-hexanone

The named product was prepared by the procedure of example 5 except that3-tert-butyloxycarbonylamino-1,1,1-trifluoro-5-methyl-2-hexanol is usedin place of 3-phenacetylamino-1,1,1-trifluoro-2-propanol.

EXAMPLE 7 N¹ -(2-Oxo-3,3-difluoro-1-isobutyl-5-hexenyl)-N² -isovalerylvalinamide

To a solution of 0.1 ml of oxalyl chloride in 2.5 ml of CH₂ Cl₂ cooledto -55° C. was added 0.17 ml of DMSO in 2.5 ml of CH₂ Cl2. Afterstirring for 5 minutes at -55° C., 0.295 g ofN'-(2-hydroxy-3,3-difluoro-isobutyl-5-hexenyl)-N² -isovalerylvalinamide, in a mixture of 2 ml of CH₂ Cl₂ and 0.4 ml of DMSO, wereadded. The mixture was stirred for 15 minutes at -55° C. and thentriethylamine (about 0.5 ml) was added to adjust the pH of the solutionto 8. The mixture was allowed to warm to room temperature, then dilutedwith CH₂ Cl₂ and washed with H₂ O, then with 1N HCl. The organic layerwas dried (MgSO4), then flash evaporated to yield 0.270 g of theexpected ketone. Rf 0.3 (CHCl₃ /Et₂ O (2:1)).

EXAMPLE 8 5-Benzoylamino-3,3-difluoro-4-oxo-6-phenylhexanoic acid

A solution of (2-benzoylamino-4,4-difluoro-7-phenyl-6-hepten-3-one (1.72g, 5 mmol) in dichloromethane (200 ml) was treated with O₃ at -78° C.for 12 minutes (about 6 mmol O₃). Dimethylsulfide (2 ml, 0.033 mol) wasadded and the solution allowed to warm to room temperature. Afterremoval of solvents (20 Torr, 30° C. and 0.05 Torr, 30° C.) a slightlycolored oil was obtained, which contained free aldehyde, present inabout 70% according to H-NMR (CHO versus 2 CH₂).

A solution of the oil in acetone (7.5 ml) was treated with aJones-solution (7.5 ml, 1M CrO₃ /H₂ SO₄) overnight. The organic layerwas separated and the aqueous phase extracted with AcOEt (4×10 ml). Thecombined organic layers were washed with brine, dried (MgSO₄) and flashevaporated to yield 1.7 g of the crude acid.

EXAMPLE 9 N¹ -(2-Oxo-3,3-Difluoro-1-isobutyl-5-carboxylpentyl)-N²-isovaleryl-valinamide

The above-named product was prepared fromN'-(2-oxo-3,3-difluoro-1-isobutyl-5-hexenyl)-N² -isovaleryl valinamideby the procedure of example 8.

EXAMPLE 106,6-Difluoro-2-phenyl-4-phenylmethyl-3-aza-1.9-dioxaspiro-(4,4)non-2-en-8-one

A solution of crude 5-benzoylamino-3,3-difluoro-4-oxo-6-phenyl hexanoicacid (1.37 g, 3.8 mmol) in 10 ml THF was kept under N² and cooled to 0°C. Pyridine (0.32 ml, 327 mg, 4.1 mmol) was added slowly. After stirringfor 10 minutes at 0° C., the solution was cooled further to -10° C., andoxalyl chloride (0.35 ml, 508 mg, 4 mmol) was added. Gas evolutionoccurred and the mixture was allowed to warm to 0° C., when a secondaddition of pyridine (0.32 ml, 327 mg, 4.1 mmol) was added slowly. Themixture was warmed to 40° C. over 30 minutes, when gas evolution hadceased. AcOEt(60 ml) and water (5 ml) were added, the phases separated,and the organic layer washed with 0.1 HCl, aqueous NaHCO₃, and water(each 2×5 ml). After drying (MgSO₄) the solvents were removed (20 Torr,40° C.) to yield 1.1 g of crude lactone derivative as a yellow coloredoil, which crystallized upon addition of hexane. Recrystallization(AcOEt/hexane, 1:10) afforded 830 mg of pure lactone derivative ascolorless needles; mp. 145° C.

EXAMPLE 11N-(5-Benzoylamino-3,3-difluoro-1,4-dioxo-6-phenylhexyl)-S-indoline-2-carboxylicacid, phenylmethyl ester

A mixture of indoline-2-carboxylic acid phenylmethylester hydrochloride(1.16 g, 0.4 mmol) in Et₂ O and H₂ O (ea. 5 ml) was treated with Na₂ CO₃(solid) and stirred for 10 min. The organic layer was separated and theaq. layer extracted with Et₂ O (2×10 ml). The combined organic phaseswere dried (MgSO₄) and flash evaporated (20 Torr, 30° C., and then 0.05Torr, 30° C). The only residue (960 mg) was dissolved in chloroform (3ml).

1 ml (about 320 mg, 1.26 mmol) of indolinecarboxylic acid phenylmethylester of the above solution was added to6,6-difluoro-2-phenyl-4-phenylmethyl-3-aza-1,9-dioxaspiro-(4,4)non-2-en-8-one(365 mg, 1.06 mmol) dissolved in 1 ml of chloroform. After stirring 40hr. at 40° C., solvents were evaporated (20 Torr, 30° C.) to give anoily residue, which was purified by chromatography on silica gel (10 g,230-400 mesh, eluent:pentane/AcOEt (20:3)). The product-containingfractions were combined and solvents removed under reduced pressure togive 500 mg of the expected peptide as an oil.

EXAMPLE 12N-(5-Benzoylamino-3,3-difluoro-1,4-dioxo-6-phenylhexyl)-(S)-indoline-2-carboxylicacid

A mixture ofN-(5-benzoylamino-3,3-difluoro-1,4-dioxo-6-phenylhexyl)-S-prolinephenylmethyl ester (500 mg, 0.84 mmol) and 100 mg Pd/C in i-PrOH (30 ml)was hydrogenated under atmospheric pressure for 12 hours at 25° C. Themixture was filtered and the filtrate flash evaporated to yield 350 mg(82%) of the expected acid as a colorless oil.

EXAMPLE 13 2,2-Difluoro-4-pentenoic acid anhydride

A suspension of silver oxide in water was prepared by adding a solutionof NaOH (1.76 g, 0.044 mol) in water (100 ml) to an aqueous solution ofsilver nitrate (7.14 g, 0.042 mol in 100 ml), decanting the supernatantliquid, washing the residue with water (3×100 ml) and adding 100 ml ofwater. To this vigorously stirred suspension was added a solution of2,2-difluoro-4-pentenoic acid (5.44 g, 0.04 mol) in water (100 ml).After 10 minutes the mixture was filtered and the filtrate concentrated(20 Torr, 30° C.) to afford a solid residue; which was dried overphosphorus pentoxide (0.05 Torr, 50° C., 24 hours) to give 8.4 g (87%)of silver 2,2-difluoro-4-pentenoate; a white amorphous powder. Asuspension of 7.3 g (0.03 mol) of the silver salt in 50 ml ofdichloromethane was stirred under nitrogen, cooled to 0° C. and then 1.9g (1.3 ml, 0.015 mol) of oxalyl chloride was added slowly. The coolingbath was removed and the reaction mixture allowed to warm up to roomtemperature. Heating to 40° C. for 30 minutes completed the reaction.Cooled again to room temperature, the supernatant liquid was decantedand the residue washed with dichloromethane (2×5 ml). The organic layerswere combined and the solvents removed by distillation at atmosphericpressure. The so-obtained oily residue was then purified by distillationto yield 2.85 g of very hydroscopic 2,2-difluoro-4-pentenoic acidanhydride, bp 78°-80° C.,/20 Torr.

EXAMPLE 14 2-Benzoylamino-1-phenyl-4,4-difluoro-6-hepten-3-one

A mixture of 2,2-difluoro-4-pentenoic acid anhydride (2.80 g, 0.011 mol)and 2-phenyl-4-phenylmethyl-5(4H)-oxazolinone (2.60 g, 0.0104 mol) wasstirred under nitrogen for 20 hours at 60° C. (oil bath temperature) togive a lightly red solution. The reaction mixture was then evaporated(0.05 Torr, 40° C.) to afford a highly viscous oil, to which underexclusion of moisture, anhydrous oxalic acid (1.0 g, 0.011 mol) wasadded and the mixture was heated for 15 minutes (110°-120° C., oil bathtemperature). After the violent gas evolution had ceased, the oil wasallowed to cool to 25° C. and then dissolved in a mixture of 40 ml ofethyl acetate and 10 ml of water. The organic layer was separated,washed with aqueous sodium bicarbonate (3×), brine, dried over magnesiumsulfate and flash evaporated (20 Torr, 30° C.) to afford a red oilyresidue (2.4 g), which was purified further by flash chromatography onsilica gel (50 g, 230-400 mesh, pentane/ethyl acetate (3:1)), Rf 0.6.The product-containing fractions were combined and evaporated to give2.2 g of a solid, which was recrystallized (ether acetate/pentane) toyield 2.04 g of 2-benzoylamino-1-phenyl-4,4-difluoro-6-hepten-3-one aswhite needles (59%); mp. 98° C.

EXAMPLE 15 6-Benzoylamino-4,4-difluoro-8-methyl-1-nonen-5-one

The above-named product was prepared from2-phenyl-4-isobutyl-5-(4H)oxazolinone by the same procedure of thepreceding example (yield 73% as oil).

EXAMPLE 16 N-(3,3,3-trifluoro-2-oxo-1-(phenylmethyl)propyl)benzamide

2.01 g (0.01 mol) of 2-phenyl-4-phenylmethyl-5(4H)oxazolinone and 2.52 g(0.012 mol) of trifluoroacetic anhydride are stirred under N₂ for 24hours at 35°-40° C. (oil bath temperature). After cooling to ambienttemperature, the excess of trifluoroacetic anhydride and the acid formedare flash evaporated (0.01 Torr, 30°-50° C.). 1.35 g (0.015 mol) offreshly sublimed anhydrous oxalic acid (0.01 Torr, 80°-100° C.) is addedand the mixture heated under stirring to 110°-120° C. (oil bathtemperature). After gas evolution has ceased (10-15 minutes) the mixtureis allowed to cool to ambient temperature and stirred for about 1-2minutes with a mixture of ethyl acetate and H₂ O (10/1). Phases areseparated and the organic layer washed with a solution of NaHCO₃ andthen brine (each 3×20 ml). Drying (MgSO₄) and flash evaporation (20 Torrand 0.01 Torr/30° C.) affords a solid which can be crystallized fromethyl acetate/hexane to yield 2.02 g (63%) of the expectedtrifluoromethyl ketone:hydrate mixture as a white powder; mp. 163° C.

EXAMPLE 17 N- 3,3-Difluoro-2-oxo-1-(phenylmethyl)propyl!benzamide

The above-named product was prepared in 50% yield by the precedingprocedure except that difluoroacetic anhydride was used in place oftrifluoroacetic anhydride; m.p. 136° C.

EXAMPLE 18 N-3,3,3-Trifluoro-2-oxo-(4-nitrophenylmethyl)propyl!benzamide

The above-named product was prepared in 55% yield by the precedingprocedure (example 16) except that2-phenyl-4(4-nitro-phenyl)methyl-5(4H) oxazolinone was used in place of2-phenyl-4-phenylmethyl-5(4H)oxazolinone:hydrate mixture; m.p. 175° C.

EXAMPLE 19 N- 2-(4-Aminoiminomethyl aminophenyl)-1-trifluoroacetylethyl!benzamide, hydrochloride

A suspension of 1.77 g (0.0054 mol) ofN-benzoyl-(4-guanidino)phenylalanine in 10 ml (1.438 g/0.07 mol) oftrifluoroacetic anhydride is stirred at 40° K. °C. (oil bathtemperature) for 20 hours. The clear solution is flash evaporated (0.01Torr, 40° C.) and treated with anhydrous oxalic acid as described in thesynthesis of N- 3,3,3-trifluoro-2-oxo-1-(phenylmethyl)propyl!benzamide,to yield 1.2 g (53%) of the expected trifluoromethyl ketone:hydratemixture as a white powder; m.p. 96° C.

EXAMPLE 20 N- 3,3,3-Trifluoro-2-oxo-1-(2-methylethyl)propyl!benzamide

The above-named product was prepared in 23% yield by the procedure ofexample 16 except that 2-phenyl-4-(2-methylethyl)-5-(4H)oxazolinone wasused in place of 2-phenyl-4-phenylmethyl-5-(4H)oxazolinone; m.p. 94° C.

EXAMPLE 21 N-{3,3,3-Trifluoro-2-oxo-1(4-phenylmethyloxycarboxamide)-butyl}propyl benzamide

The above-named product (as an oil) was prepared in 56% yield by theprocedure of example 16 except that2-phenyl-4(4-phenylmethyloxycarboxamido)butyl-5-(4H)oxazolinone was usedin place of 2-phenyl-4-phenylmethyl-5-(4H)oxazolinone.

EXAMPLE 22 N-(1-Trifluoroacetyl-3-methyl butyl)benzamide

The above-named product (as an oil) was prepared in 33% yield by theprocedure of example 16 except that2-phenyl-4-isobutyl-5-(4H)-oxazolinone was used in place of2-phenyl-4-phenylmethyl-5-(4H)-oxazolinone.

EXAMPLE 23 N-(3,3,3-Trifluoro-2-oxo-propyl)benzamide

A solution of 7.57 g hippuric acid and 17.4 ml of trifluoroaceticanhydride in 60 ml of anhydrous acetone was stirred at 25° C. for 16hours under N₂ to yield a red precipitate, which is isolated byfiltration. Refluxing the red solid in 50 ml of H₂ O for 1 hour gave asolution, which was extracted with AcOEt. The organic layer was dried(MgSO₄) and flash evaporated to yield crude product which isrecrystallized from benzene to give 4.15 g of analytically pure product;m.p. 105° C. (decomp).

EXAMPLE 24 3-Benzoylamino-1,1,1-trifluoro-2-propanol

A solution of 10 g (0.263 mol) of NaBH₄ in 100 ml of H₂ O was added to14.8 g (59.4 mmol) of N-(3,3,3-trifluoro-2-oxo-propyl)benzamide in 1000ml of H₂ O. After stirring for 2 hours at 25° C., the solution wasacidified with concentrated HCl (pH 1), basified by adding NaOH pellets(pH 10) and extracted with AcOEt (3×500 ml). After drying (MgSO₄), theorganic layer was flash evaporated to give 11 g of a white solid, whichwas recrystallized from CHCl₃ to yield 10.0 g (72%) of puretrifluoromethylalcohol; m.p. 156° C.

EXAMPLE 25 6-Benzoylamino-4,4-difluoro-8-methyl-1-nonen-5-ol

The above-named product was prepared from6-benzoyl-amino-4,4-difluoro-8-methyl-1-nonen-5-one by example 24 exceptthat the alcohol was purified by chromatography on silica gel (eluentEtOAc/hexane (1/5)); m.p. 110° C.

EXAMPLE 26 3-Benzoylamino-1,1,1-trifluoro-4-methyl-2-pentanol

The above-named product was prepared fromN-(3,3,3-trifluoro-2-oxo-1-(1-methylethyl)propyl)benzamide by example 24in 77% yield; m.p. 150° C.

EXAMPLE 27 3-Benzoylamino-1,1,1-trifluoro-5-methyl-2-hexanol

The above-named product was prepared fromN-(1-trifluoroacetyl-3-methylbutyl)benzamide by the procedure of example24 in 80% yield.

EXAMPLE 28 3-Amino-1,1,1-trifluoro-2-propanol hydrochloride

A mixture of 3 g (12.9 mmol) of3-benzoylamino-1,1,1-trifluoro-2-propanol in 26 ml of H₂ O, 26 ml ofconcentrated HCl and 26 ml of ethanol was refluxed for 20 hours, thenconcentrated under reduced pressure. The residue was dissolved in waterand extracted with diethyl ether. The aqueous layer was thenconcentrated to give a solid residue which was recrystallized fromisopropanol/diethyl ether to yield 1.37 g of the fluorinated aminoalcohol.

EXAMPLE 29 3-Amino-1,1,1-trifluoro-4-methyl-2-pentanol hydrochloride

The above-named product was prepared from3-benzoyl-amino-1,1,1-trifluoro-4-methyl-2-pentanol in 75% yield by theprocedure of example 28. Rf 0.37 (AcOEt/Et₃ N (20:1)).

EXAMPLE 30 3-Amino-1,1,1-trifluoro-5-methyl-2-hexanol hydrochloride

The above-named product was prepared from the corresponding3-benzoylamino derivative. m.p. 283° C.; Rf 0.78 (EtOH/NH₄ OH, (70/30))by the procedure of example 28.

EXAMPLE 31 6-Amino-4,4-difluoro-8-methyl-1-nonen-5-ol hydrochloride

The above-named product was obtained by the procedure of example 28 in89% yield from the corresponding 6-benzoylamino derivative.

EXAMPLE 32 4-N-tert-Butoxycarbonylamino 2,2-difluoro 3-hydroxy 6-methylheptanoic acid ethyl ester

To a refluxing suspension of 0.196 g of activated zinc wool in anhydroustetrahydrofuran (3 ml) is added a solution of 0.618 g (3mmol) of ethylbromodifluoroacetate in anhydrous THF (1 ml). After the reaction starts,a solution of 0.5 g (2.32 mmol) of N-tert-butoxycarbonyl leucinal isadded. The mixture is left at gentle reflux for 1 hour. The reactionmixture is then cooled, quenched by addition of ethyl acetate (10 ml),brine and 1M KHSO₄. The organic layer is dried over anhydrous MgSO₄,evaporated and purified by flash chromatography (silica gel, 10%EtOAc/cyclohexane) yield, 0.210 g, Rf 0.65 (EtOAc/cyclohexane, 1:1).

EXAMPLE 33 4-N-tert-Butoxycarbonylamino 2,2-difluoro 3-hydroxy 6-methylheptanoic acid

A solution of 0.0285 g (0.68 mmol) of LiOH, H2O in water (2 ml) is addedat 0° C. to a mixture of 0.210 g (0.62 mmol) of4-N-tert-butoxycarbonylamino 2,2-difluoro 3-hydroxy 6-methyl heptanoicacid, ethyl ester in 1,2-dimethoxyethane (DME) (5 ml). The temperatureis allowed to raise slowly to room temperature. The mixture is stirredat room temperature overnight. The mixture is diluted with water (10 ml)washed with diethyl ether (10 ml). The aqueous layer is acidified toabout pH 2 with 0.1N HCl, extracted with diethyl ether (2×10 ml). Thecombined organic layers is washed with brine and dried over anhydrousMgSO₄. Filtration and removal of the solvent in vacuo yields theexpected acid which is recrystallized from diethyl ether/pentane.

EXAMPLE 34 4-N-tert-Butoxycarbonylamino 2,2-difluoro 3-hydroxyN-(1-isoamylaminocarbonyl ethyl)-6-methylheptanamide

To a mixture of 0.194 g (1 mmol) of alanine isoamyl amide hydrochloridein methylene chloride (or DMF) (5 ml) is added 0.101 g (1 mmol) oftriethylamine at 0 KC.4-N-tert-butoxycarbonylamino-2,2-difluoro-3-hydroxy-6-methyl heptanoicacid (0.311 g) and 1-hydroxybenzotriazole (0.202 g) are added, followedby the addition of DCC (0.206 g, 1 mmole) in methylene chloride (5 ml).The reaction mixture is allowed to warm up slowly to room temperatureand stirred for 12 hours at that temperature. Dicyclohexylurea isfiltered, and the filtrate evaporated under reduced pressure. Theresidue is dissolved in ethyl acetate, washed successively with cold 1NHCl, 1N NaOH and dried over anhydrous MgSO₄. The amide is purified bycolumn chromatography (silica gel, EtOAc/cyclohexane; 1:1, Rf 0.22(EtOAc/cyclohexane, 1:1).

EXAMPLE 35 4-Amino 2,2-difluoro 3-hydroxy N-(isoamylaminocarbonyl-ethyl)6-methyl-heptanamide hydrochloride

4-N-tert-Butoxycarbonylamino 2,2-difluoro 3-hydroxyN-1-isoamylaminocarbonylethyl)-6-methyl heptanamide (0.457 g) isdissolved in a solution of about 4N HCl in diethylether (5 ml) andstirred at room temperature for 14 hours. After the removal of excessreagent under reduced pressure, the solid residue was triturated withether to form a solid which is dried, in vacuo for 8 hours. Rf 0.63(AcOH/butanol/H₂ O; 2:6:2).

EXAMPLE 36 4- (2-N-isovaleryl-3-methyl-1-oxobutyl)amino!2,2-difluoro3-hydroxy-N-(1-isoamylaminocarbonylethyl) 6-methyl heptanamide

To a solution of 0.130 g (0.33 mmol) of 4-amino 2,2-difluoro 3-hydroxyN-(1-isoamylaminocarbonylethyl) 6-methyl-heptanamide HCl in THF (10 ml)is added 0.034 g (0.33 mmol) of N-methyl morpholine at room temperature.After 10 min., the mixture is cooled to 0° C.; a solution of 0.103 g(0.50 mmol) of DCC in THF (1 ml) is then added, followed by the additionof 0.100 g (0.50 mmol) of N-isovaleryl valine. Stirring is continued for15 hours, while the temperature is allowed to rise to room temperature.The precipitate is filtered off and the filtrate rinsed with THF. Thesolvent is evaporated in vacuo; the residue is purified bychromatography (silica gel, CH₃ OH/CHCl₃ 2:98) yielding 0.06 g of theexpected amide. Rf: 0.45 (CH₃ OH/CHCl₃ 8:92).

EXAMPLE 37 4-(2-N-isovalerylamino-3-methyl-1-oxobutyl)amino!2,2-difluoro-N-(1-isoamylaminocarbonylethyl)6-methyl 3-oxo heptanamide

A solution of 0.214 g (0.40 mmol) of 4-2-N-isovalerylamino-3-methyl-1-oxobutyl)amino!2,2-difluoro3-hydroxy-N-(1-isoamylaminocarbonylethyl) 6-methyl heptanamide in CH₂Cl₂ (4 ml) is added to a suspension of pyridinium dichromate (0.228 g)and 3° Angstroms molecular sieves (0.336 g), containing 20 microliter ofglacial acetic acid. Stirring is continued for 15 hours at roomtemperature. Florisil (0.200 g) is added, stirring continued for 0.25hours and the mixture filtered. Removal of the solvent andchromatography (silica gel, ethyl acetate/acetone 7:3) afford theexpected ketone. Rf: 0.3 (ethyl acetate/chloroform 1:1).

EXAMPLE 38 4-N-tert-butoxycarbonylamino 2,2-difluoro 6-methyl 3-oxoheptanoic acid, ethyl ester

The title compound was prepared in 65% yield from the alcohol describedin example 32 by the preceding procedure. The ketone was purified bychromatography (silica gel, ethyl acetate/cyclohexane 1:9).

EXAMPLE 39 4-amino 2,2-difluoro 6-methyl 3-oxo heptanoic acid, ethylester hydrochloride

The BOC protecting group of the ketone of example 38 is cleaved usingthe same procedure as for the amide described in example 35. m.p:127°-128° C. (decomp).

EXAMPLE 40 Ethyl-3-keto-2-methyl-4,4,4-trifluorobutanoate

Sodium hydride (7.05 g of a 50% oil dispersion, 0.15 mol) was washed 3times with 25 ml of dimethoxyethane to remove the oil and then suspendedin 220 ml of dimethoxyethane, under an argon atmosphere and cooled in anice bath. A solution of ethyl 3-keto-4,4,4-trifluorobutanoate (25.77 g,0.14 mol) in 25 ml of dimethoxyethane was added dropwise from anaddition funnel to the stirred suspension. After the addition wascompleted, the cooling bath was removed and the reaction mixture stirredfor 30 minutes past the cessation of hydrogen gas evolution. Methyliodide (43.0 ml, 0.70 mole) was added by syringe and the reactionmixture refluxed overnight. The reaction was cooled to room temperatureand poured into a separatory funnel containing a 1:1:1 mixture ofsaturated ammonium chloride:brine:water. The layers were separated andthe aqueous phase extracted with 100 ml ether. The combined organicphase and ether extract was washed with brine, dried over magnesiumsulfate and filtered. The solvents were removed by distillation atatmospheric pressure using a Vigreaux column leaving ethyl3-keto-2-methyl-4,4,4-trifluorobutanoate as the pot residue. Rf:(EtAc/hexane - 20:80)

EXAMPLE 41 Ethyl 3-hydroxy-2-methyl-4,4,4-trifluorobutanoate

To a solution of ethyl 3-keto-2-methyl-4,4,4-trifluorobutanoate (20.1 g,0.10 moles) in 250 ml of absolute ethanol, cooled in an ice bath, wasadded sodium borohydride (1.0 g, 0.25 moles) in portions with stirring.The cooling bath was removed and the reaction stirred at roomtemperature for 30 minutes. Acetone (5 ml) was added to quench anyremaining sodium borohydride and the solvents removed by distillation atatmospheric pressure using a Vigreaux column. The residue was dilutedwith 200 ml of methylene chloride and poured into a separatory funnelcontaining 75 ml of a 1:1:1 mixture of saturated ammoniumchloride:brine:water. The layers were separated and the aqueous phaseextracted with methylene chloride (3×25 ml). The combined organic phaseand methylene chloride extracts were dried over magnesium sulfate,filtered and distilled at atmospheric pressure to remove the solvents.The residue was then distilled at reduced pressure (20 mmHg) using aVigreaux column to give ethyl3-hydroxy-2-methyl-4,4,4-trifluorobutanoate, bp 78°-84° C., 20 mmHg.

EXAMPLE 42 3-Hydroxy-2-methyl-4,4,4-trifluorobutanamide

Into a solution of ethyl 3-hydroxy-2-methyl-4,4,4-trifluorobutanoate(11.4 g, 51.0 mmol) in 85 ml of methanol, cooled in an ice bath, wasbubbled in anhydrous ammonia for several minutes. The reaction flask wassealed with a septum and stirred at room temperature for 6 days. Themixture was concentrated using a rotary evaporator and the residuedistilled at reduced pressure using a vacuum pump to remove allcomponents with a boiling point less than 25° C. at 0.05 mmHg leavingtrifluorobutanamide (5.8 g, 33.9 mmol) as the pot residue.

EXAMPLE 43 3-Hydroxy-4,4,4-trifluoro-2-butylamine hydrochloride

To potassium hydroxide pellets (15.4 g of 85% pellets, 0.23 moles)dissolved in 45 ml of water and cooled in an ice bath was added bromine(2.7 ml, 51.4 mmol). After several minutes, a solution of3-hydroxy-2-methyl-4,4,4-trifluorobutanamide (8.0 g, 46.8 mmol) in 45 mlwater, pre-cooled in an ice bath, was added. The reaction was stirred atice bath temperatures for 20 minutes and then at room temperature for 30minutes. Finally, the reaction was heated on a steam bath for 30minutes. The reaction mixture was cooled to room temperature and pouredinto a separatory funnel where it was extracted with methylene chloride(3×50 ml). The aqueous layer was then saturated with solid sodiumchloride and extracted further with two portions of methylene chloride(25 ml). The combined organic extracts were dried over magnesiumsulfate, filtered and the solvent removed at ambient temperature on arotary evaporator. The residue was dissolved in anhydrous ether (250 ml)and anhydrous hydrogen chloride gas bubbled through the reactionmixture. A white precipitate formed and the suspension was cooled in anice bath. The precipitate was filtered and then recrystallized fromacetone ether to give 3-hydroxy-4,4,4-trifluoro-2-butylaminehydrochloride, Rf: 0.25 (NH₄ OH/CH₃ OH/CH₂ Cl₂ - 2:10:88).

EXAMPLE 44 L-Alanine methyl ester hydrochloride

To a suspension of L-alanine (25.0 g, 0.28 moles) in 125 ml of methanol,cooled in an ice-methanol bath, was added thionyl chloride (21.0 ml,0.29 moles) dropwise at a rate such that the internal reactiontemperature was maintained at 5° C. or less. After the addition wascompleted, the cooling bath was removed and the reaction mixture warmedto 45° C. for 2 hours. The reaction mixture was filtered to remove asmall amount of yellow solid and the filtrate concentrated using arotary evaporator. To the resultant oil was added tetrahydrofuran (50ml) and the mixture evaporated to dryness on a rotary evaporator. Theresidue was placed under high vacuum to yield an off white solid. Ether(300 ml) was added to the solid and the suspension digested on a steambath. Cooling and filtering gave L-alanine methyl ester hydrochloride(37.2 g, 0.26 mmol).

EXAMPLE 45 Boc-L-Alanine methyl ester

To a stirred suspension of L-alanine methyl ester hydrochloride (10.0 g,71.6 mmol) in methylene chloride (220 ml) under an argon atmosphere wasadded triethylamine (10.0 ml, 71.6 mmol). Fifteen minutes later, asolution of di-tert-butyl dicarbonate (15.3 g, 70.2 mmol) in methylenechloride (30 ml) was added dropwise. After the addition was complete,the reaction mixture was stirred at room temperature overnight. Thereaction mixture was poured into a separatory funnel containing 50 mlwater and the layers separated. The organic layer was washed with 0.5Nhydrochloric acid (2×50 ml) and brine (50 ml). The organic layer wasthen dried over magnesium sulfate, filtered and the majority of solventevaporated using a rotary evaporator. The last traces of solvent wereremoved under high vacuum to give Boc-L-alanine methyl ester (14.27 g,70.2 mmol).

EXAMPLE 46 Boc-L-Alaninal

Boc-L-alanine methyl ester (5.0 g, 24.6 mmol) was dissolved in drytoluene (150 ml) under an argon atmosphere and cooled in a dryice-acetone bath. To this vigorously stirred solution was added asolution of diisobutylaluminumhydride (1.0M in hexanes, 61.5 ml, 61.5mmol), pre-cooled in a dry ice-acetone bath, via a transfer needle.After 6 minutes, the reaction was carefully quenched with methanol (4ml) and the mixture allowed to warm to room temperature. The reactionmixture was poured into a separatory funnel containing 250 ml ether and200 ml of ice cold 0.25N hydrochloric acid. The layers were separatedand the organic layer was washed with 0.25N hydrochloric acid (3×80 ml)and brine (50 ml). The organic layer was dried over magnesium sulfate,filtered and concentrated using a rotary evaporator at ambienttemperature. The residue was chromatographed using hexanes - 30%ethyl-acetate to give Boc-L-alaninal. The compound may also be preparedby the technique described in Synthesis, 1983, pg. 676.

EXAMPLE 47 (3S)-3-Amino-2-hydroxybutanoic acid

To a suspension of Boc-L-alaninal (2.5 g, 14.4 mmol) in ice cold water(30 ml) was added an ice cold solution of sodium bisulfite (1.5 g, 14.4mmol) in water (10 ml). The resultant suspension was stirred at ice bathtemperature overnight. To the resultant solution was added ethyl acetate(200 ml) and then a solution of potassium cyanide (0.9 g, 14.4 mmol) inwater (10 ml). The reaction mixture was stirred at room temperature for4 hours and then poured into a separatory funnel and the layersseparated. The organic layer was washed with water (2×100 ml) and brine(75 ml), then dried over magnesium sulfate, filtered and concentratedusing a rotary evaporator. The cyanohydrin was dissolved in dioxane (50ml) and concentrated hydrochloric acid (50 ml) added. The reactionmixture was refluxed overnight and then cooled to room temperature. Thereaction mixture was poured into a separatory funnel containing ether(100 ml) and the layers separated. The aqueous layer was extracted witha further 100 ml ether and then evaporated to dryness on a rotaryevaporator. The resultant residue was dissolved in water (30 ml) and thepH adjusted to approximately 7 with 2N ammonium hydroxide. This solutionwas placed on a Biorad AG 50 W-X8 H⊕ resin column and eluted with 2Nammonium hydroxide. Combination of the appropriate fractions andevaporation gave crude (3S)-3-amino-2-hydroxybutanoic acid which wasthen recrystallized from water-acetone to give the desired product (1.05g, 8.8 mmol) as a white solid.

EXAMPLE 48 Methyl (3S)-3-amino-2-hydroxybutanoate

Into a suspension of (3S)-3-amino-2-hydroxybutanoic acid (1.0 g, 8.4mmol) in methanol (25 ml) was bubbled anhydrous hydrogen chloride gasuntil a solution resulted. After a solution resulted, the reaction wascooled in an ice bath and saturated with hydrogen chloride. The coolingbath was removed and the reaction stirred at room temperature for 3.5hours. The solvent was removed on a rotary evaporator at ambienttemperature and the resultant residue dissolved in methanol (25 ml),cooled in an ice bath and saturated with hydrogen chloride gas. Warmingof the reaction solution to room temperature and removal of the solventon a rotary evaporator gave an oil. To this oil was added triethylamine(15 ml) followed by the minimum amount of methanol (about 15 ml) neededto dissolve the initial gummy solid. The solution was cooled in an icebath and ether (75 ml) added in portions with stirring. The precipitatedtriethylamine hydrochloride was filtered and the filtrate evaporated togive methyl (3S)-3-amino-2-hydroxybutanoate.

EXAMPLE 49 Boc-L-alanyl-L-proline benzyl ester

Boc-L-alanine (19.5 g, 0.10 mol) was dissolved in dry tetrahydrofuran(90 ml) under an argon atmosphere in a flask fitted with an overheadstirrer and an internal thermometer. The solution was cooled to -15° C.and N-methylmorpholine (11.4 ml, 0.10 mol) was added followed byisobutylchloroformate (13.4 ml, 0.10 mol) at such a rate as to maintainthe internal reaction temperature at -10° to -15° C. Five minutes afterthe addition was completed, a solution of L-proline benzyl esterhydrochloride (25.2 g, 0.10 mol) and N-methylmorpholine (11.4 ml, 0.10mol) in chloroform (90 ml) was added dropwise at such a rate as tomaintain the internal reaction temperature at -10° to -15° C. After theaddition was completed, the reaction mixture was allowed to slowly warmto room temperature and then stirred at room temperature overnight. Thereaction mixture was concentrated using a rotary evaporator, the residuediluted with ethyl acetate (500 ml)/0.2N hydrochloric acid (100 ml) andpoured into a separatory funnel. The layers were separated and theaqueous phase extracted with a further 150 ml ethyl acetate. Thecombined organics were washed with 0.2N hydrochloric acid (2×100 ml),water (100 ml), saturated sodium bicarbonate (2×100 ml), again withwater (100 ml) and finally brine (100 ml). The organic phase was driedover magnesium sulfate, filtered and concentrated on a rotaryevaporator. Chromatography using ethyl acetate-hexane as the eluent gaveBoc-L-alanyl-L-proline benzyl ester, Rf: 0.15 (EtOAc/hexane - 30:70).

EXAMPLE 50 L-Alanyl-L-proline benzyl ester hydrochloride

Into a solution of Boc-L-alanyl-L-proline benzyl ester (31.6 g, 83.94mmol) in ethyl acetate (400 ml) cooled in an ice bath was bubbledhydrogen chloride gas for 15 minutes. The addition of gas was ceased,the cooling bath removed and the solution stirred at room temperaturefor 1.5 hours. Concentration using a rotary evaporator followed bydrying the residue in a vacuum desiccator over potassium hydroxidepellets overnight! gave L-alanyl-L-proline benzylester hydrochloride(25.5 g, 81.5 mmol).

EXAMPLE 51 Boc-L-alanyl-L-alanyl-L-proline benzyl ester

L-alanyl-L-proline benzyl ester hydrochloride (13.0 g, 41.6 mmol) wasdissolved in methylene chloride (650 ml) under an argon atmosphere in aflask fitted with an over-head stirrer. N-methylmorpholine (4.8 ml, 43.6mmol) was syringed into the solution and, after 5 minutes, Boc-L-alanine(7.9 g, 41.6 mmol) was added followed by1-ethoxy-carbonyl-2-ethoxy-1,2-dihydroquinoline (11.8 g, 47.8 mmol). Theresulting solution was stirred at room temperature overnight. Thereaction mixture was poured into a separatory funnel containing water(300 ml) and the layers separated. The aqueous layer was extracted withchloroform (200 ml) and the combined organic extracts were washed with0.5N hydrochloric acid (3×200 ml), water (2×200 ml), saturated sodiumbicarbonate (2×200 ml) and brine (200 ml). The organic layer was thendried over magnesium sulfate, filtered and concentrated on a rotaryevaporator. Addition of ether-hexane gave crudeBoc-L-alanyl-L-alanyl-L-proline benzyl ester which could berecrystallized from ethyl acetate-hexane to give the pure product (15.1g) mp 124°-126° C.

EXAMPLE 52 L-Alanyl-L-alanyl-L-proline benzyl ester hydrochloride

Into a solution of Boc-L-alanyl-L-alanyl-L-proline benzyl ester (25.5 g,57.0 mmol) in ethyl acetate (650 ml) cooled in an ice bath was bubbledhydrogen chloride gas for 15 minutes at which time bubbling was ceased.The cooling bath was removed and the solution stirred at roomtemperature for 1.5 hours. The reaction mixture was concentrated on arotary evaporator and the resultant gummy solid dissolved in methylenechloride-hexane. Removal of the solvents gaveL-alanyl-L-alanyl-L-proline benzyl ester hydrochloride which was driedover potassium hydroxide pellets in a vacuum desiccator overnight toyield 21.09 (54.7 mmol) of the desired product.

EXAMPLE 53 Methoxysuccinyl-L-alanyl-L-alanyl-L-proline benzyl ester

To a solution of L-alanyl-L-alanyl-L-proline benzyl ester hydrochloride(19.2 g, 50.0 mmol), mono-methyl succinate (6.6 g, 50.0 mmol) and1-hydroxybenzotriazole.xH₂ O (16.9 g) in N,N-dimethylformamide (125 ml)under an argon atmosphere and cooled in an ice bath was addedN-methylmorpholine (5.5 ml, 50.0 mmol). After 5 minutes,N,N'-dicyclohexylcarbodiimide (11.9 g, 57.5 mmol) was added, the coolingbath removed and the reaction mixture stirred at room temperatureovernight. The reaction mixture was filtered and the filtrate pouredinto a separatory funnel containing chloroform (750 ml)/0.5Nhydrochloric acid (250 ml). The layers were separated and the aqueousphase extracted with chloroform (200 ml). The combined organic extractswere washed with 0.5N hydrochloric acid (2×250 ml), water (2×250 ml),saturated sodium bicarbonate (2×250 ml) and brine (250 ml). The organiclayer was dried over magnesium sulfate, filtered and concentrated on arotary evaporator. The last traces of solvent were removed using avacuum pump and the residue chromatographed using acetone-ethyl acetateas the eluent. The resultant crude MeOSuc-L-alanyl-L-alanyl-L-prolinebenzyl ester was recrystallized from ethyl acetate to give pure productm.p. 124°-127° C.

EXAMPLE 54 MeOSuc-L-alanyl-L-alanyl-L-proline

Into a Parr flask flushed with argon containing 4.0 g of 10% palladiumon charcoal catalyst was added tert-butanol (775 ml) and thenMeOSuc-L-alanyl-L-alanyl-L-proline benzyl ester (13.0 g, 28.2 mmols).The mixture was shaken under 30 psi of hydrogen at 30°-40° C. overnight.The mixture was filtered through celite and the filtrate concentrated ona rotary evaporator. The residue, was azeotroped with chloroform-hexaneto remove the last traces of tert-butanol and then dried under highvacuum to give MeOSuc-L-alanyl-L-alanyl-L-proline (10.4 g, 28.0 mmol).

EXAMPLE 55 Acetyl-L-prolyl-L-alanyl-L-proline benzyl ester

Ac-L-proline (3.05 g, 19.41 mmol) was dissolved in dry tetrahydrofuran(100 ml) under an argon atmosphere in a flask fitted with an overheadstirrer and an internal thermometer. The solution was cooled to -15° C.and N-methylmorpholine (2.13 ml, 19.41 mmol) was added followed byisobutylchloroformate (2.51 ml, 19.41 mmol) at such a rate as tomaintain the internal reaction temperature at -10° to -15° C. Fiveminutes after the addition was completed, a solution ofL-alanyl-L-proline benzyl ester hydrochloride (6.08 g, 19.41 mmol) inchloroform (70 ml) was added followed by a second portion ofN-methylmorpholine (2.13 ml, 19.41 mmol) at such a rate as to maintainthe internal reaction temperature at -10° to -15° C. The reactionmixture was then allowed to slowly warm to room temperature and stirredat room temperature for 2.5 hours. The reaction mixture was concentratedto a small residue on a rotary evaporator, diluted with chloroform (500ml) and poured into a separatory funnel where it was washed with 0.2Nhydrochloric acid (3×200 ml) and 5% sodium bicarbonate (200 ml). Theorganic layer was dried over magnesium sulfate, filtered, concentratedon a rotary evaporator and chromatographed using methylenechloride-methanol as an eluent to give Ac-L-prolyl-L-alanyl-L-prolinebenzyl ester; Rf: 0.35 (CH₃ OH/CH₂ Cl₂ - 7:93).

EXAMPLE 56 Acetyl-L-prolyl-L-alanyl-L-proline

Into a Parr flask flushed with argon containing 450 mg of 10% palladiumon charcoal catalyst was added a solution ofAc-L-prolyl-L-alanyl-L-proline benzyl ester in (1.0 g, 2.41 mmol)absolute ethanol (100 ml). The contents were shaken under 40 psi ofhydrogen overnight at room temperature. The mixture was filtered throughcelite and the filtrate concentrated on a rotary evaporator to givecrude Ac-L-prolyl-L-alanyl-L-proline which was crystallized fromtetrahydrofuran-methanol-ether to give the desired product (0.57 g) in73% yield.

EXAMPLE 57 1,1,1-Trifluoro-3-(N-acetylprolyl)alanylprolylamino!butan-2-ol

Ac-L-prolyl-L-alanyl-L-proline (1.17 g, 3.61 mmol) was suspended in dryacetonitrile (55 ml) under an argon atmosphere in a flask fitted with anoverhead stirrer and internal thermometer. The suspension was cooled to-15° C. and N-methylmorpholine (0.40 ml, 3.61 mmol) was added followedby isobutylchloroformate (0.47 ml, 3.61 mmol) at such a rate as tomaintain the internal reaction temperature at -10° to -15° C. Tenminutes after the addition was completed, a mixture of3-hydroxy-4,4,4-trifluoro-2-butyl-amine hydrochloride (0.65 g, 3.61mmol) and N-methylmorpholine (0.40 ml, 3.61 mmol) in chloroform (25 ml)was added at such a rate as to maintain the internal reactiontemperature at -10° to -15° C. The reaction mixture was allowed to warmslowly to room temperature and then stirred at room temperature for 4hours. The reaction mixture was evaporated on a rotary evaporator to anoily residue which was dissolved in water (65 ml) and treated with amixed bed resin (J. T. Baker--ANGMI-615, 17 g). After 15 minutes themixture was filtered and the filtrate evaporated on a rotary evaporator.Chromatography using methylene chloride - 10% methanol as the eluentgave the above-named product, (0.37 g) in 23% yield.

EXAMPLE 58 1,1,1-Trifluoro-3-(N-acetylprolyl)alanylprolylamino!-butane-2,2-diol

To a solution of oxalyl chloride (72 μl, 0.83 mmol) in methylenechloride (1 ml) under an argon atmosphere and cooled in a dryice-acetone bath was added dimethylsulfoxide (0.12 ml, 1.65 mmol) withstirring. After 5 minutes, a solution of the compound of example 57(0.25 g, 0.55 mmol) in methylene chloride (1.5 ml) was added. Thereaction mixture was stirred for 15 minutes, triethylamine (0.50 ml,3.58mmol) then added and the reaction warmed to room temperature for 30minutes. The reaction mixture was placed directly onto a silica gelcolumn and eluted with methylene chloride-methanol. Trituration of theresultant oily solid with ether-hexane and filtration gave theabove-named product, (50 mg, 0.11 mmol).

EXAMPLE 59 3- (N-acetylprolyl)alanylprolylamino!-2-hydroxybutanoic acid,methyl ester

Ac-L-prolyl-L-alanyl-L-proline (0.65 g, 2.00 mmol) was suspended in dryacetonitrile (20 ml) under an argon atmosphere in a flask fitted with anoverhead stirrer and internal thermometer. The suspension was cooled to-15° C. and N-methylmorpholine (0.22 ml, 2.00 mmol) was added followedby isobutylchloroformate (0.26 ml, 2.00 mmol) at such a rate as tomaintain the internal reaction temperature at -10° to -15° C. After 10minutes, a solution of methyl (3S)-3-amino-2-hydroxybutanoate (0.53 g,4.00 mmol) in chloroform (2.5 ml) was added at such a rate as tomaintain the internal reaction temperature at -10° to -15° C. Thereaction mixture was slowly warmed to room temperature and then stirredfor 3 hours. The reaction mixture was evaporated on a rotary evaporator,the residue dissolved in water (20 ml) and treated with a mixed bedresin (J. T. Baker--ANGMI-615, 11.0 g). After 15 minutes the mixture wasfiltered and the filtrate evaporated on a rotary evaporator.Chromatography using methylene chloride-methanol as the eluent gave theabove-named product (0.32 g) in 36% yield.

EXAMPLE 60 3-(N-acetylprolyl)alanylprolylamino!-2,2-dihydroxybutanoic-acid, methylester

To a stirred solution of oxalyl chloride (0.12 ml, 1.43 mmol) inmethylene chloride (1.5 ml) under an argon atmosphere and cooled in adry ice-acetone bath was added dropwise a solution of dimethylsulfoxide(0.20 ml, 2.86 mmol) in methylene chloride (1.5 ml). After 5 minutes, asolution of the product of example 59 (0.32 g, 0.72 mmol) in methylenechloride (1.5 ml) was added and the reaction mixture stirred for 25minutes. Triethylamine (0.50 ml, 3.58 mmol) was added and the reactionmixture warmed to room temperature. The reaction mixture was placeddirectly onto a silica gel column and eluted with methylenechloride-methanol. Evaporation of the appropriate fractions on a rotaryevaporator, addition of water (3 ml) to the residue and evaporation gavethe above-named product.

EXAMPLE 61 (N-acetylprolyl)alanylprolylamino!-2,2-dihydroxybutanoic acid

To a solution of the product of example 60 (0.10 g, 0.23 mmol) in water(4 ml) cooled in an ice bath was added 1N lithium hydroxide (0.50 ml ofan aqueous solution, 0.50 mmol). After 1 hour the pH of the reactionmixture was adjusted to 4.5 to 5.0 with 1N hydrochloric acid and thereaction evaporated on a rotary evaporator. The residue waschromatographed using methylene chloride-methanol as the eluent.Evaporation of the appropriate fractions, addition of water (2 ml) tothe residue and evaporation gave the above-named product (65 mg) in 64%yield.

EXAMPLE 62 Boc-L-alanyl-L-alanyl-L-proline

A Parr flask was flushed with argon and charged with 10% palladium oncharcoal (0.74 g), followed by the addition ofBoc-L-alanyl-L-alanyl-L-proline benzyl ester (1.8 g, 4.0 mmol) dissolvedin tert-butanol (300 ml). The reaction mixture shaken under 30 psi ofhydrogen at 35° C. for 5 hr. After cooling to room temperature, ethanol(50 ml) was added and the solution was filtered through celite and thefiltrate concentrated on a rotary evaporator. The residue was azeotropedwith chloroform-hexane to remove the last traces of tert-butanol andthen dried under high vacuum to give Boc-L-alanyl-L-alanyl-L-proline(1.40 g, 3.9mmol) in 98% yield.

EXAMPLE 63 1,1,1-Trifluoro-3-(N-tert-butyloxycarbonylalanyl)alanylprolylamino!-4-methylpentan-2-ol

To a solution of Boc-L-alanyl-L-alanyl-L-proline (1.0 g, 2.80 mmol) indry acetonitrile (25 ml) was added N-methylmorpholine (0.34 ml, 3.06mmol). The solution was cooled to -20° C. and isobutylchloroformate(0.37 ml, 2.88 mmol) was added dropwise. To this solution, a pre-cooled(-20° C.) mixture of 3-amino-1,1,1-trifluoro-4-methyl-2-pentanolhydrochloride (0.61 g, 2.91 mmol), N,N-dimethylformamide (4 ml) andN-methylmorpholine (0.34, 3.06 mmol) was added. The reaction mixture wasstirred at -20° C. for 4 hr, allowed to warm to room temperature andstirred overnight. Removal of the solvents in vacuo produced a paleyellow residue, which was purified by flash chromatography using ethylacetate as an eluent to give 1,1,1-Trifluoro-3-(N-tert-butyloxycarbonylalanyl)alanylprolylamino!-4-methylpentane-2-ol(1.09 g, 2.1 mmol) in 76% yield.

EXAMPLE 64 1,1,1-trifluoro-3-N-tert-butyloxycarbonylalanyl)alanylprolylamino!-4-methylpentan-2-one

A solution of oxalyl chloride (0.078 ml, 0.9 mmol) in methylene chloride(2 ml) was cooled to -55° C. and dimethylsulfoxide (0.125 ml, 1.8 mmol)was added dropwise. The solution was stirred for 5 min, followed by theaddition of 1,1,1-trifluoro-3-N-tert-butyloxycarbonylalanyl)alanylprolylamino!-4-methylpentan-2-ol(260 mg, 0.53 mmol) in methylene chloride (1.5 ml). The mixture wasstirred for 15 min and triethylamine (0.45 ml, 3.2 mmol) was added. Thereaction mixture was allowed to warm to room temperature, the solventwas removed in vacuo and the crude product was loaded directly onto asilica gel column (230-400 mesh) for purification. Elution with ethylacetate gave 1,1,1-trifluoro-3-N-tert-butyloxycarbonylalanyl)alanylprolylamino!-4-methylpentan-2-one(180 mg, 0.37 mmol) in 70% yield.

EXAMPLE 65 1,1,1-Trifluoro-3-alanyl-alanylprolylamino!-4-methylpentan-2-one

A solution of 1,1,1-Trifluoro-3(N-tert-butyloxycarbonylalanyl)alanyl-prolylamino!-4-methylpentan-2-one(180 mg, 0.35 mmol) in ethyl acetate (50 ml) was cooled to 0° C. andtreated with hydrogen chloride gas for 5 min. The reaction mixture wasstirred at 0° C. for 1.5 hr, followed by removal of solvent in vacuo.1,1,1-Trifluoro-3- alanylalanylprolylamino!-4-methylpentan-2-one (151mg, 0.34 mmol) was obtained in 96% yield and was used for subsequentreactions without purification.

EXAMPLE 66 Dansyl peptide1,1,1-Trifluoro-3-(alanylalanylprolylamino)-4-methylpentan-2-one

To a suspension of1,1,1-Trifluoro-3-(alanylalanylprolylamino)-4-methylpentan-2-one (50 mg,0.11 mmol) in methylene chloride (1 ml), was added N-methylmorpholine(50 mg, 0.5 mmol). The solution was stirred for 5 min and dansylchloride (50 mg) then added. The reaction mixture was stirred for 2 h atroom temperature with the exclusion of light and then loaded directlyonto a silica gel column (230-400 mesh) for purification. Elution withethylacetate gave the dansylated peptide (48 mg, 0.07 mmol) in 68%yield.

EXAMPLE 67 N¹-(2-Methoxyethoxymethoxy-3,3-difluoro-1-isobutyl-5-hexenyl-N²-isovaleryl valinamide

To 0.211 g of sodium hydride (55%, 4.83 mmol) in 3 ml of DMF at 0° C.was added 1.8 g (4.6 mmol) of N¹-(2-hydroxy-3,3-difluoro-1-isobutyl-5-hexenyl)-N² -isovalerylvalinamide, in 5 ml of DMF. After stirring OKC for 10 min.,methoxyethoxymethylchloride (0.659 g, 5.29 mmol in 3 ml DMF) was added,the mixture stirred for 10 min. at 0° C. and overnight at roomtemperature. Workup with water/Et₂ O gave, after purification by flashchromatography (CHCl₃ /Et₂ O, 2:1) 1.4 g of the desired product.

EXAMPLE 68 N¹-(2-Methoxyethoxymethoxy-3,3-difluoro-1-isobutyl-4-carboxybutyl)-N²-isovaleryl valinamide

The above-named compound was prepared from N¹-2-methoxyethoxymethoxy-3,3-difluoro-1-isobutyl-5-hexenyl)-N²-isovaleryl valinamide by the procedure described in example 8 usingequivalent proportions and conditions.

EXAMPLE 69 N¹ -(2-Methoxyethoxymethoxy-3,3-difluoro-1-isobutyl-4-1-(Isoamylaminocarbonyl)ethyl!methylamino carbonylbutyl)-N² -isovalerylvalinamide

The above-named compound was prepared from N¹-(2-mehoxyethoxymethoxy-3,3-difluoro-1-isobutyl-4-carboxybutyl)-N²-isovaleryl valinamide by the procedure described in example 49.Proportions: 1.50 g (3.02 mmol) peptide acid in 10 ml THF, 0.306 g (0.33ml, 3.02 mmol) N-methyl morpholine, 0.412 g (3.02 mmol)isobutylchloroformate, N-methyl alanine isoamylamide hydrochloride (0.63g, 3.02 mmol) and N-methyl morpholine (0.306 g, 3.02 mmol) in 5 ml THF.Flash chromatography (EtOAc/Pentane, 2:1) gives 0.3 g of the above-namedcompound. From 1.50 g of the peptide acid, using the procedure ofexample 49 there is produced, after purification by flashchromatography, 0.39 g of the desired product.

EXAMPLE 70 N¹ -(2-Hydroxy-3,3-difluoro-1-isobutyl-4 1-(isoamylaminocarbonyl)ethyl!-methylamino!carbonylbutyl)-N² -isovaleryl valinamide

A mixture of 0.3 g (0.46 mmol) of N¹-(2-methoxyethoxymethoxy-3,3-difluoro-1-isobutyl-4-1-(isoamylaminocarbonyl)ethyl!-methylamine!carbonylbutyl)-N² -isovalerylvalinamide and 0.52 g (2.31 mmol) of ZnBr₂ in 3 ml CH₂ Cl₂ was stirredfor 24 h at room temperature. Flash chromatography (EtOAc) gives 0.11 gof the above-named alcohol.

EXAMPLE 71 N¹ -(2-Oxo-3,3-difluoro-1-isobutyl-41-(isoamylamino)ethyl!methylamino!carbonylbutyl)-N² -isovalerylvalinamide

The above-named compound was prepared from N¹-(2-Hydroxy-3,3-difluoro-1-isobutyl-41-(isoamylamino)ethyl!methylamino!carbonylbutyl)-N² -isovalerylvalinamide by the procedure described in example 7. Proportions:Oxalylchloride (0.176 mmol, 0.0224 mg) in 0.5 ml CH₂ Cl₂, 0.0275 mg(0.352 mmol) DMSO, 90 mg of alcohol in 1.5 ml CH₂ Cl₂ (at -55° C.) 0.081g Et₃ N (0.8 mmol). Flash chromatography (EtOAc) gave 0.02 g ofabove-named compound.

EXAMPLE 72 4-N-tert-butoxycarbonylamino 2,2-difluoro 3-hydroxy 5-methylhexanoic acid, ethyl ester

The title compound was prepared in 35% yield from L-BOC valinal usingthe same procedure as for the ester, described in example 32. Rf=0.52(EtOAc/C₆ H₁₂ 1:1)

EXAMPLE 73 4-Amino 2,2-difluoro 3-hydroxy 5-methyl hexanoic acid, ethylester hydrochloride

The Boc protecting group of the alcohol of example 72 is cleaved usingthe same procedure as for the amide described in example 35, mp 182° C.

EXAMPLE 74 4- methoxysuccinyl L-alanyl-L-alanyl-L-prolyl!amino2,2-difluoro 3-hydroxy 5-methyl hexenoic acid, ethyl ester

To a stirred solution of 0.371 g (1 mmol) of MeOSuc-L-Ala-L-Ala-L-ProOHin dry acetonitrile (10 ml) under nitrogen was added 0.106 g (1.05 mmol)of N-methyl-morpholine. The resultant solution was cooled to -20° C.Isobutyl chloroformate (0.136 g, 1 mmol) was added to the cooledreaction mixture. After 10 min. a solution of 0.275 g (1.05 mmol) of4-amino 2,2-difluoro 3-hydroxy 5-methyl hexanoic acid, ethyl esterhydrochloride and 0.106 g (1.05 mmol) of N-methylmorpholine in dry DMF(2 ml) was added to the cooled mixture. The reaction mixture was stirredat -20° C. for 4 hours and then allowed to warm to room temperature.After stirring 15 hours at room temperature the mixture is concentratedand placed under high vacuum at 40° C. to remove all the DMF.Chromatography (silica gel, ethyl acetate/acetone 7:3) yielded theexpected alcohol in 85% yield. Rf: 0.38 (ethyl acetate/acetone 1:1).

EXAMPLE 75 4- Methoxysuccinyl-L-alanyl-L-alanyl-L-prolyl!amino2,2-difluoro 5-methyl 3-oxo hexanoic acid, ethyl ester

The title compound was obtained in 65% yield from the alcohol of example74 using the procedure described in example 37, mp: 96°-97° C.

The foregoing describes in detail the generic and specific aspects ofthe scope of the invention as well as the manner of making and using theinvention. In addition thereto, although such procedures are known inthe art, references setting forth state of art procedures by which thecompounds may be evaluated for their biochemical effects is alsoincluded herein.

For example, human elastase is assayed in vitro using chromophoricpeptides, succinylalanylalanylalanyl-p-nitroanilide (A1),methoxysuccinylalanylalanylprolylvalyl-p-nitroanilide (A2), and others,all of which are available commercially. The assay buffer, pH 8.0, andassay techniques are similar to those described by Lottenberg et al.(A3, A4). Enzyme is purified from human sputum (A5), although recentlyit has become commercially available. Kinetic characterization ofimmediate inhibitors is by means of the Dixon plot (A6), whereas thecharacterization of slow- and/or tight-binding inhibitors used dataanalysis techniques reviewed by Williams and Morrison (A7).

Similarly, the other proteases are assayed and effects of inhibitors areassessed in vitro by similar spectroscopic techniques: cathepsin G (A2);thrombin (A3); chymotrypsin (A8); trypsin (A9); plasmin (A3); C₁esterase (A10); urokinase (A3); plasminogen activator (A11); acrosin(A12); beta-lactamase (A13); cathepsin B (A14); pepsin (A15); cathepsinD (A16) and leucine aminopept dase (A17). Pseudomonas elastase ismeasured in a coupled assay procedure using a human elastase substrateand microsomal aminopeptidase.

Radiometric assays of angiotensin I-converting enzyme and enkephalinaseand their inhibitors are based on the procedure of Ryan (A18) and usetritiated substrate purchased from Ventrex Laboratories, Inc.Radioimmunoassay issued for studies with renin (A19). C₃ -convertase ismeasured as described by Tack et al. (A20).

The individual assay references are elaborated upon by the following:

A1. The synthesis and analytical use of a highly sensitive andconvenient substrate of elastase. J. Bieth, B. Spiess and C. G. Wermuth,Biochemical Medicine, 11 (1974) 350-375.

A2. Mapping the extended substrate binding site of cathepsin G and humanleukocyte elastase. Studies with peptide substrates related to the alpha1-protease inhibitor reactive site. K. Nakajima, J. C. Powers, B. M.Ashe and M. Zimmerman, The Journal of Biological Chemistry, 254 (1979)4027-4032.

A3. Assay of coagulation proteases using peptide chromogenic andfluorogenic substrates. R. Lottenberg, U. Christensen, C. M. Jackson andP. L. Coleman, in, Methods in Enzymology (L. Lorand, ed), AcademicPress, New York, 1979, vol. 80, pp. 341-361.

A4. Solution composition dependent variation in extinction coefficientsfor p-nitroaniline. R. Lottenberg and C. M. Jackson, Biochimica etBiophysica Acta, 742 (1983) 558-564.

A5. A rapid procedure for the large scale purification of elastase andcathepsin G from human sputum. R. R. Martodam, R. J. Baugh, D. Y.Twumasi and I. E. Liener, Preparative Biochemistry, 9 (1979) 15-31.

A6. The determination of enzyme inhibitor constants. M. Dixon, TheBiochemical Journal, 55 (1953) 170-171.

A7. The kinetics of reversible tight-binding inhibition. J. W. Williamsand J. F. Morrison, in, Methods in Enzymology (D. L. Purich, ed),Academic Press, New York, 1979, vol. 63, pp. 437-467.

A8. Two convenient spectrophotometric enzyme assays. A biochemistryexperiment in kinetics. J. A. Hurlbut, T. N. Ball, H. C. Pound and J. L.Graves, Journal of Chemical Education, 50 (1973) 149-151.

A9. The preparation and properties of two new chromogenic substrates oftrypsin. B. F. Erlanger, N. Kokowsky and W. Cohen, Archives ofBiochemistry and Biophysics, 95 (1961) 271-278.

A10. The human complement system serine proteases Clr and Cls and theirproenzymes. R. B. Sim, in, Methods in Enzymology (L. Lorand, ed),Academic Press, New York, 1979, vol. 80, pp. 26-42.

A11. Extrinsic plasminogen activator and urokinase. J. H. Verheijen, C.Kluft, G. T. G. Chang and E. Mullaart, in, Methods of Enzymatic Analysis(H. U. Bergmeyer, J. Bergmeyer and M. Grassl, eds.), Verlag Chemie,Weinheim, 1984, third edition, vol. 5, pp. 425-433.

A12. Sperm acrosin. W. Mueller-Esterl and H. Fritz, in, Methods inEnzymology (L. Lorand, ed), Academic Press, New York, 1979, vol. 80, pp.621-632.

A13. Novel method for detection of beta-lactamases by using achromogenic cephalosporin substrate. C. H. O'Callaghan, A. Morris, S. M.Kirby and A. H. Shingler, Antimicrobial Agents and Chemotherapy, 1(1972) 283-288.

A14. Cathepsin B, cathepsin H, and cathepsin L. A. J. Barrett and H.Kirschke, in, Methods in Enzymology (L. Lorand, ed), Academic Press, NewYork, 1979, vol. 80, pp. 535-561.

A15. Pepsins, gastricsins and their zymogens. A. P. Ryle, in, Method ofEnzymatic Analysis (H. U. Bergmeyer, J. Bergmeyer and M. Grassl, eds),Verlag Chemie, Weinheim, 1984, third edition, vol. 5, pp. 223-238.

A16. Cathepsin D, cathepsin E. V. Turk, T. Lah and I. Kregar, in,Methods of Enzymatic Analysis (H. U. Bergmeyer, J. Bergmeyer and M.Grassl, eds), Verlag Chemie, Weinheim, 1984, third edition, vol. 5, pp.211-222.

A17. Amino acid arylamidase. J. C. M. Hafkenscheid, in, Methods ofEnzymatic Analysis (H. U. Bergmeyer, J. Bergmeyer and M. Grassl, eds),Verlag Chemie, Weinheim, 1984, third edition, vol. 5, pp. 11-15.

A18. Angiotensin I converting enzyme (kininase II). J. W. Ryan, in,Methods of Enzymatic Analysis (H. U. Bergmeyer, J. Bergmeyer and M.Grassl, eds), Verlag Chemie,Weinheim, 1984, third edition, vol. 5, pp.20-34.

A19. Renin. T. Inagami and M. Naruse, in, Methods of Enzymatic Analysis(H. U. Bergmeyer, J. Bergmeyer and M. Grassl, eds), Verlag Chemie,Weinheim, 1984, third edition, vol. 5, pp. 249-258.

A20. The third, fourth, and fifth components of human complement:isolation and biochemical properties. B. F. Tack, J. Janatova, M. L.Thomas, R. A. Harrison and C. H. Hammer, in, Methods in Enzymology (L.Lorand, ed), Academic Press, New York, 1979, vol. 80, pp. 64-101.

By following the techniques referenced above, as well as by utilizationof other known techniques, as well as by comparison with compounds knownto be useful for treatment of the above-mentioned disease states, it isbelieved that adequate material is available to enable one of ordinaryskill in the art to practice the invention. Of course, in the end-useapplication of the compounds of this invention,the compounds arepreferably formulated into suitable pharmaceutical preparations such astablets, capsules or elixers, for oral administration or in sterilesolutions or suspensions for parenteral administration. The compounds ofthis invention can be administered to patients (animals and human) inneed of such treatment in a dosage range of 0.01-10 mg per kg of bodyweight per day. As stated above,the dose will vary depending on severityof disease, weight of patient and other factors which a person skilledin the art will recognize.

Typically the compounds described above are formulated intopharmaceutical compositions as discussed below.

About 10 to 500 mg of a compound or mixture of compounds of Formula I ora physiologically acceptable salt is compounded with a physiologicallyacceptable vehicle, carrier, excipient, binder, preservative,stabilizer, flavor, etc., in a unit dosage form as called for byaccepted pharmaceutical practice. The amount of active substance inthese compositions or preparations is such that a suitable dosage in therange indicated is obtained.

Illustrative of the adjuvants which may be incorporated in tablets,capsules and the like are the following: a binder such as gumtragacanth, acacia, corn starch or gelatin; an excipient: such asmicrocrystalline cellulose; a disintegrating agent such as corn starch,pregelatinized starch, alginic acid and the like; a lubricant such asmagnesium stearate; a sweetening agent such as sucrose, lactose orsaccharin; a flavoring agent such as peppermint,oil of wintergreen orcherry. When the dosage unit form is a capsule, it may contain inaddition to materials of the above type, a liquid carrier such as fattyoil. Various other materials may be present as coatings or to otherwisemodify the physical form of the dosage unit. For instance,tablets may becoated with shellac, sugar or both. A syrup or elixer may contain theactive compound, sucrose as a sweetening agent, methyl and propylparabens as preservatives, a dye and a flavoring such as cherry ororange flavor.

Sterile compositions for injection can be formulated according toconventional pharmaceutical practice by dissolving or suspending theactive substance in a vehicle such as water for injection, a naturallyoccurring vegetable oil like sesame oil, coconut oil, peanut oil,cottonseed oil, etc. or a synthetic fatty vehicle like ethyl oleate orthe like. Buffers, preservatives, antioxidants and the like can beincorporated as required.

While the invention has been described in connection with specificembodiments thereof, it will be understood that it is capable of furthermodifications and this application is intended to cover any variations,uses, or adaptations of the invention following, in general, theprinciples of the invention and including such departures from thepresent disclosure as come within known or customary practice within theart to which the invention pertains and as may be applied to theessential features hereinbefore set forth, and as follows in the scopeof the appended claims.

We claim:
 1. A compound useful for inhibiting plasmin of the formula##STR64## the hydrates thereof, and the pharmaceutically acceptablesalts thereof whereinX is X₁ or X₂,wherein X₁ is --CF₃, --CF₂ H, --CO₂R₃ or --CONHR₃, X₂ is ##STR65## R₁ is -P₂ -P₃ -P_(g) with P₂ beingselected from Group F, P₃ is selected from Groups B or F, and P_(g) isan optional Group K amino protecting group, R₂ is a side chain of anamino acid selected from Groups A and J R₃ is hydrogen, C₁₋₄ straight orbranched alkyl, phenyl, benzyl, cyclohexyl or cyclohexylmethyl, R₄ isthe side chain of an α-amino acid, R₅ is an α-amino acid or a peptidehaving up to 3 α-amino acids sequenced in their P₂ ' to P₄ ' positions,or is deleted, Y is --NHR₃ or OR₃ wherein the said α-amino acid andpeptide moieties are selected from Groups A, B, C, D, E, F, G and J, andK is a terminal amino protecting group, members of these groups beingGroupA: Lys and Arg B: Glu, Asp C: Ser, Thr, Gln, Asn, Cys, His D: Pro,Ind E: Ala, Leu, Ile, Val, n-Val, Met, n-Leu and N-methyl derivatives F:Phe, Tyr, Trp, Nal (1), and N-methyl derivatives G: Gly, SarJ:--NHCH(--C═O)--CH₂ Φ(ρ-)NHC(═NH)--NH₂ (J-1), --NHCH(--C═O)--CH₂Φ(ρ-)C(═NH)--NH₂ (J-2), --NHCH(--C═O)--ΦCH₂ NHC(═NH)--NH₂ (J-3), and--NHCH(--C═O)--ΦCH₂ C(═NH)--NH₂ (J-4) with Φ representing phenyl, K:Acetyl (Ac), Succinyl (Suc), Benzoyl (Bz), t-Butyloxycarbonyl (Boc),Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva),Methoxysuccinyl (MeOSuc), 1-Adamantanesulphonyl (AdSO₂),1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl (2-CBZ) and such otherterminal amino protecting groups which are functionally equivalentthereto.
 2. A compound of claim 1 selected from thegroupDNS-Glu-Phe-Lys-CHF₂, DNS-Glu-Phe-Lys-COOH, DNS-Glu-Phe-Lys-CF₃,DNS-Glu-Phe-Lys-COOMe, and DNS-Glu-Phe-Lys-CF₂ COOEt.
 3. A compounduseful for inhibiting C₁ -esterase of the formula ##STR66## the hydratesthereof, and the pharmaceutically acceptable salts thereof whereinXgenerically is X₁ or X₂ wherein X₁ is --CF₃, --CF₂ H, --CO₂ R₃ or--CONHR₃, X₂ is ##STR67## R₂ is a side chain of an amino acid selectedfrom Groups A and J, R₁ generically is -P₂ -P_(g) with P₂ being selectedfrom Groups E, G, D, C, F, A and B, and P_(g) is selected from Group K,R₄ is a side chain of an amino acid selected from Group E, R₅ isselected from Group E and Y is NH₂, R₃ is hydrogen, C₁₋₄ straight orbranched alkyl, phenyl, benzyl, cyclohexyl or cyclohexylmethyl, Y is--NHR₃ or OR₃,wherein Groups A, B, C, D, E, F, G, J and K are asfollows: GroupA: Lys and Arg B: Glu, Asp C: Ser, Thr, Gln, Asn, Cys, HisD: Pro, Ind E: Ala, Leu, Ile, Val, n-Val, Met, n-Leu and N-methylderivatives F: Phe, Tyr, Trp, Nal (1), and N-methyl derivatives G: Gly,Sar J:--NHCH(--C═O)--CH₂ Φ(ρ-)NHC(═NH)--NH₂ (J-1), --NHCH(--C═O)--CH₂Φ(ρ-)C(═NH)--NH₂ (J-2), --NHCH(--C═O)--ΦCH₂ NHC(═NH)--NH₂ (J-3), and--NHCH(--C═O)--ΦCH₂ C(═NH)--NH₂ (J-4) with Φ representing phenyl, K:Acetyl (Ac), Succinyl (Suc), Benzoyl (Bz), t-Butyloxycarbonyl (Boc),Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva),Methoxysuccinyl (MeOSuc), 1-Adamantanesulphonyl (AdSO₂),1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl (2-CBZ) and such otherterminal amino protecting groups which are functionally equivalentthereto.
 4. A compound of claim 3 selected from the group consistingofCBZ-Ala-Arg-CF₃, CBZ-Ala-Arg-COOH, CBZ-Ala-Arg-COOMe,CBZ-Ala-(p-gua)-Phe-CF₂ COOEt, and CBZ-Ala-(p-gua)-Phe CF₂ Ala!NH₂.
 5. Acompound useful for inhibiting C₃ -convertase of the formula ##STR68##the hydrates thereof, and the pharmaceutically acceptable salts thereofwhereinX is X₁ or X₂,wherein X₁ is --CF₃, --CF₂ H, --CO₂ R₃ or --CONHR₃,X₂ is ##STR69## R₄ is a side chain of an amino acid selected from GroupE, R₅ Y is OR₃, R₂ is a side chain of an amino acid selected from GroupsA or J, R₁ is -P₂ -P₃ -P_(g) with P₂ being selected from Groups E or F,P₃ is selected from Groups E or F, and P₄ is selected from Group K R₃ ishydrogen, C₁₋₄ straight or branched alkyl, phenyl, benzyl, cyclohexyl orcyclohexylmethyl,wherein Groups A, E, F, J and K are as follows: GroupA:Lys and Arg E: Ala, Leu, Ile, Val, n-Val, Met, n-Leu and N-methylderivatives F: Phe, Tyr, Trp, Nal (1), and N-methyl derivativesJ:--NHCH(--C═O)--CH₂ Φ(ρ-)NHC(═NH)--NH₂ (J-1), --NHCH(--C═O)--CH₂Φ(ρ-)C(═NH)--NH₂ (J-2), --NHCH(--C═O)--ΦCH₂ NHC(═NH)--NH₂ (J-3), and--NHCH(--C═O)--ΦCH₂ C(═NH)--NH₂ (J-4) with Φ representing phenyl, K:Acetyl (Ac), Succinyl (Suc), Benzoyl (Bz), t-Butyloxycarbonyl (Boc),Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva),Methoxysuccinyl (MeOSuc), 1-Adamantanesulphonyl (AdSO₂),1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl (2-CBZ) and such otherterminal amino protecting groups which are functionally equivalentthereto.
 6. A compound of claim 5 selected from the group consistingofBz-Leu-Ala-Arg-CF₃, Bz-Leu-Ala-Arg-CF₂, Bz-Leu-Ala-Arg CF₂ -Ala!OCH₂Φ, and Bz-Leu-Ala-Arg-COOCH₂ Φ.
 7. A compound useful for inhibitingUrokinase of the formula ##STR70## the hydrates thereof, and thepharmaceutically acceptable salts thereof whereinX is X₁ or X₂,wherein Xis --CF₃, --CF₂ H, --CO₂ R₃ or --CONHR₃, X₂ is ##STR71## R₄ is a sidechain of an amino acid of Group E, R₅ is Group E, and Y is NH₂, R₁ is-P₂ -P₃ with P₂ being selected from Groups E and G, and P₃ is selectedfrom Group B, R₂ is a side chain of an amino acid selected from Groups Aand J, R₃ is hydrogen, C₁₋₄ straight or branched alkyl, phenyl, benzyl,cyclohexyl or cyclohexylmethyl,wherein Groups A, B, E, G and J are asfollows: GroupA: Lys and Arg B: Glu, Asp E: Ala, Leu, Ile, Val, n-Val,Met, n-Leu and N-methyl derivatives G: Gly, Sar J:--NHCH(--C═O)--CH₂Φ(ρ-)NHC(═NH)--NH₂ (J-1), --NHCH(--C═O)--CH₂ Φ(ρ-)C(═NH)--NH₂ (J-2),--NHCH(--C═O)--ΦCH₂ NHC(═NH)--NH₂ (J-3), and --NHCH(--C═O)--ΦCH₂C(═NH)--NH₂ (J-4) with Φ representing phenyl.
 8. A compound of claim 7selected from the group consisting ofH-Glu-Gly-Arg-CF₂ H,H-Glu-Gly-Arg-CF₃, H-Glu-Gly-Arg-COOH, H-Glu-Gly-Arg-CONH₂, andH-Glu-Gly-(p-gua)Phe- CF₂ Ala!-Ala-NH₂.
 9. A compound useful forinhibiting a plasminogen activator of the formula ##STR72## the hydratesthereof, and the pharmaceutically acceptable salts thereof whereinX isX₁ or X₂,wherein X₁ is --CF₃, --CF₂ H, --CO₂ R₃ or --CONHR₃, X₂ is##STR73## R₄ is a side chain of an amino acid of Group E, R₅ is Group E,Y is NH₂ R₁ generically is -P₂ -P₃ -P_(g) wherein P₂ is Gly, P₃ isselected from Group B, and P_(g) is an optional Group K protectinggroup, and R₂ is a side chain of an amino acid selected from Groups Aand J, R₃ is hydrogen, C₁₋₄ straight or branched alkyl, phenyl, benzyl,cyclohexyl or cyclohexylmethyl,wherein Groups A, B, E, J and K are asfollows: GroupA: Lys and Arg B: Glu, Asp E: Ala, Leu, Ile, Val, n-Val,Met, n-Leu and N-methyl derivatives J:--NHCH(--C═O)--CH₂Φ(ρ-)NHC(═NH)--NH₂ (J-1), --NHCH(--C═O)--CH₂ Φ(ρ-)C(═NH)--NH (J-2),--NHCH(--C═O)--ΦCH₂ NHC(═NH)--NH₂ (J-3), and --NHCH(--C═O)--ΦCH₂C(═NH)--NH₂ (J-4) with Φ representing phenyl, K: Acetyl (Ac), Succinyl(Suc), Benzoyl (Bz), t-Butyloxycarbonyl (Boc), Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva), Methoxysuccinyl (MeOSuc),1-Adamantanesulphonyl (AdSO₂), 1-Adamantaneacetyl (AcAc),2-Carboxybenzoyl (2-CBZ) and such other terminal amino protecting groupswhich are functionally equivalent thereto.
 10. A compound of claim 9selected from the group consisting ofDNS-Glu-Gly-Arg-COOMe,DNS-Glu-Gly-Arg-CF₃, DNS-Glu-Gly-Arg-COOH, DNS-Glu-Gly-(p-gua)Phe-CHF₂,DNS-Glu-Gly-(p-gua)PheCF₂ COOEt.
 11. A compound useful for inhibitingacrosin of the formula ##STR74## the hydrates thereof, and thepharmaceutically acceptable salts thereof whereinX is X₁ or X₂,whereinX₁ is --CF₃, --CF₂ H, --CO₂ R₃ or --CONHR₃, X₂ is ##STR75## R₄ is a sidechain of an amino acid of Group E, R₅ is Group E, or is deleted and Y isNH₂, R₁ is -P₂ -P₃ -P_(g) with P₂ being selected from Group E, P₃ isselected from Group E, P_(g) is an optional Group K protecting group, R₂is a side chain of an amino acid selected from Groups A and J, R₃ ishydrogen, C₁₋₄ straight or branched alkyl, phenyl, benzyl, cyclohexyl orcyclohexylmethyl,wherein Groups A, E, J and K are as follows: GroupA:Lys and Arg E: Ala, Leu, Ile, Val, n-Val, Met, n-Leu and N-methylderivatives J:--NHCH(--C═O)--CH₂ Φ(ρ-)NHC(═NH)--NH₂ (J-1),--NHCH(--C═O)--CH₂ Φ(ρ-)C(═NH)--NH₂ (J-2), --NHCH(--C═O)--ΦCH₂NHC(═NH)--NH₂ (J-3), and --NHCH(--C═O)--ΦCH₂ C(═NH)--NH₂ (J-4) with Φrepresenting phenyl, K: Acetyl (Ac), Succinyl (Suc), Benzoyl (Bz),t-Butyloxycarbonyl (Boc), Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS),Isovaleryl (Iva), Methoxysuccinyl (MeOSuc), 1-Adamantanesulphonyl(AdSO₂), 1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl (2-CBZ) and suchother terminal amino protecting groups which are functionally equivalentthereto.
 12. A compound of claim 11 a selected from the group consistingofBoc-Leu-Leu-Arg-CF₂ H, Boc-Leu-Leu-Arg-CF₃, Boc-Leu-Leu-Arg-COOH,Boc-Leu-Leu-(p-gua)Phe- CF₂ Ala!AlaNH₂, and Boc-Leu-Leu-(p-gua)PheCF₂CONH₂.
 13. A compound useful for inhibiting cathepsin B of the formula##STR76## the hydrates thereof, and the pharmaceutically acceptablesalts thereof whereinX is X₁ or X₂ wherein X₁ is --CF₃, --CF₂ H, --CO₂R₃ or --CONHR₃, X₂ is ##STR77## R₄ is a side chain of an amino acidselected from Group E, R₅ is selected from Groups G, E or F and Y is OH,R₁ is (a)-P₂ -P_(g) or (b)-P₂ -P₃ -P_(g) wherein for(a) P₂ is selectedfrom Groups E and F and P_(g) is selected from Group K, and (b) P₂ isselected from Groups E and F, -P₃ being selected from Groups E and F,and P_(g) is selected from Group K, R₂ is a side chain of an amino acidselected from Group A, J or ThrCOCH₂ Φ, R₃ is hydrogen, C₁₋₄ straight orbranched alkyl, phenyl, benzyl, cyclohexyl or cyclohexylmethyl,whereinGroups A, E, F, G, J and K are as follows: GroupA: Lys and Arg E: Ala,Leu, Ile, Val, n-Val, Met, n-Leu and N-methyl derivatives F: Phe, Tyr,Trp, Nal (1), and N-methyl derivatives G: Gly, Sar J:--NHCH(--C═O)--CH₂Φ(ρ-)NHC(═NH)--NH₂ (J-1), --NHCH(--C═O)--CH₂ Φ(ρ-)C(═NH)--NH₂ (J-2),--NHCH(--C═O)--ΦCH₂ NHC(═NH)--NH₂ (J-3), and --NHCH(--C═O)--ΦCH₂C(═NH)--NH₂ (J-4) with Φ representing phenyl, K: Acetyl (Ac), Succinyl(Suc), Benzoyl (Bz), t-Butyloxycarbonyl (Boc), Carbobenzoxy (CBZ),Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva), Methoxysuccinyl (MeOSuc),1-Adamantanesulphonyl (AdSO₂), 1-Adamantaneacetyl (AcAc),2-Carboxybenzoyl (2-CBZ) and such other terminal amino protecting groupswhich are functionally equivalent thereto.
 14. A compound useful asinhibitors of renin of the formula ##STR78## the hydrates thereof, andthe pharmaceutically acceptable salts thereof whereinX is X₁ or X₂wherein X₁ is --CF₃, --CF₂ H, --CO₂ R₃ or --CONHR₃, X₂ is ##STR79## R₄is a side chain of an amino acid selected from Groups E, F or G, R₅ is-P₂ '-P₃ '-P₄ ', P₂ ' being from Groups E, F or is deleted, with P₃ 'being selected from Groups E or F or is deleted with P₄ ' being selectedfrom Groups E, C or F or is deleted and Y is OH or NH₂, R₂ is a sidechain of an amino acid selected from Groups E or F or iscyclohexylmethylene, R₁ generically is -P₂ -P₃ -P₄ -P₅ -P_(g) wherein P₂is selected from Groups E, C or F, P₃ is selected from Groups E or F, P₄is selected from Groups E, D, F or is deleted, P₅ is selected fromGroups E, C, F or is deleted, and P_(g) is selected from Group K R₃ ishydrogen, C₁₋₄ straight or branched alkyl, phenyl, benzyl, cyclohexyl orcyclohexylmethyl,wherein Groups C, D, E, F, G and K are as follows:GroupC: Ser, Thr, Gln, Asn, Cys, His D: Pro, Ind E: Ala, Leu, Ile, Val,n-Val, Met, n-Leu and N-methyl derivatives F: Phe, Tyr, Trp, Nal (1),and N-methyl derivatives G: Gly, Sar K: Acetyl (Ac), Succinyl (Suc),Benzoyl (Bz), t-Butyloxycarbonyl (Boc), Carbobenzoxy (CBZ), Tosyl(Ts),Dansyl (DNS), Isovaleryl (Iva), Methoxysuccinyl (MeOSuc),1-Adamantanesulphonyl (AdSO₂), 1-Adamantaneacetyl (AcAc),2-Carboxybenzoyl (2-CBZ) and such other terminal amino protecting groupswhich are functionally equivalent thereto.
 15. A compound of claim 14selected from the group consisting ofCBZ-Nal(l)-His-Leu-CHF₂,CBZ-Nal(l)-His-Leu-CF₃, CBZ-Nal(l)-His-Leu-CF₂ -COOEt,MeOSuc-His-Pro-Phe-His-Leu- CF₂ -Val!Ile-His-OH, MeOSuc-Pro-Phe-His-Leu-CF₂ -Val!Ile-His-OH, MeOSuc-His-Phe-His-Leu- CF₂ -Val!Ile-His-OH,MeOSuc-His-Pro-Phe-His-Leu- CF₂ -Val!Ile-OH, MeOSuc-His-Pro-Phe-His-Leu-CF₂ -Val!His-OH, BOC-His-Pro-Phe-His-Leu CF₂ -Val!-Ile-His-OH,BOC-His-Pro-Phe-His-Leu- CF₂ -CO!-Ile-His-NH₂, and BOC-Pro-Phe-His-LeuCF₂ -Val!-Ile-His-NH₂.
 16. A compound useful for inhibiting pepsin ofthe formula ##STR80## the hydrates thereof, and the pharmaceuticallyacceptable salts thereof whereinX is X₁ or X₂ wherein X₁ is --CF₃, --CF₂H, --CO₂ R₃ or --CONHR₃, X₂ is ##STR81## R₄ is a side chain of an aminoacid selected from the Groups E, G and F, R₅ is selected from Groups Eand F and Y is --NHCH₂ CH(CH₃)₂ or --NHCH₂ CH₂ CH(CH₃)₂, R₁ is -P₂ -P₃-P_(g) with P₂ being selected from Groups E or F, P₃ is selected fromGroups E or F or is deleted and P_(g) is selected from Group K, and R₂is a side chain of an amino acid selected from Groups E and F R₃ ishydrogen, C₁₋₄ straight or branched alkyl, phenyl, benzyl, cyclohexyl orcyclohexylmethyl,wherein Groups E, F, G and K are as follows: GroupE:Ala, Leu, Ile, Val, n-Val, Met, n-Leu and N-methyl derivatives F: Phe,Tyr, Trp, Nal (1), and N-methyl derivatives G: Gly, Sar K: Acetyl (Ac),Succinyl (Suc), Benzoyl (Bz), t-Butyloxycarbonyl (Boc), Carbobenzoxy(CBZ), Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva), Methoxysuccinyl(MeOSuc), 1-Adamantanesulphonyl (AdSO₂), 1-Adamantaneacetyl (AcAc),2-Carboxybenzoyl (2-CBZ) and such other terminal amino protecting groupswhich are functionally equivalent thereto.
 17. A compound of claim 16selected from the group consisting ofIva-Val-Leu-CF₂ -CO-Ala-NH-CH₂ CH₂CH(CH₃)₂, Iva-Val-Val-Leu CF₂ -Gly!-N(Me)Ala-NHCH₂ CH₂ CH(CH₃)₂,Iva-Val-Val-Leu-CHF₂, and Iva-Val-Val-Leu-CF₃.
 18. A compound useful forinhibiting cathepsin D of the formula ##STR82## the hydrates thereof,and the pharmaceutically acceptable salts thereof whereinX is X₁ or X₂wherein X₁ is --CF₃, --CF₂ H, --CO₂ R₃ or --CONHR₃, X₂ is ##STR83## R₄is a side chain of an amino acid selected from Groups E and F, R₅ isselected from Groups E and F, Y is --NH(CH₂)₂ CH(CH₃)₂ or --NHCH₂CH(CH₃)₂, R₁ generically is -P₂ -P₃ -P_(g) with P₂ being selected fromGroups E and F, P₃ is selected from Groups E and F, and P_(g) isselected from Group K, and R₂ is a side chain of an amino acid selectedfrom Groups E and F R₃ is hydrogen, C₁₋₄ straight or branched alkyl,phenyl, benzyl, cyclohexyl or cyclohexylmethyl,wherein Groups E, F, andK are as follows: GroupE: Ala, Leu, Ile, Val, n-Val, Met, n-Leu andN-methyl derivatives F: Phe, Tyr, Trp, Nal (1), and N-methyl derivativesK: Acetyl (Ac), Succinyl (Suc), Benzoyl (Bz), t-Butyloxycarbonyl (Boc),Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva),Methoxysuccinyl (MeOSuc), 1-Adamantanesulphonyl (AdSO₂),1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl (2-CBZ) and such otherterminal amino protecting groups which are functionally equivalentthereto.
 19. A compound of claim 18 selected from the group consistingofCBZ-Val-Val-Phe-CF₂ -CO-Ala-Iaa CBZ-Val-Val-Phe-CF₂ H,CBZ-Val-Val-Phe-CF₃, CBZ-Val-Val-Phe CF₂ -Phe!Ala-NH(CH₂)₂ CH(CH₃)₂, andCBZ-Val-Val-Phe CF₂ -Phe!Ala-NHCH₂ CH(CH₃)₂, with Iaa being isoamylamide.
 20. A compound useful as an ACE inhibitor of the formula##STR84## the hydrates thereof, and the pharmaceutically acceptablesalts thereof whereinX is X₂ wherein X₂ is ##STR85## R₄ is a side chainof an amino acid selected from Groups E or G, R₅ is selected from GroupsA, B, C, D, E, F and G, R₁ is selected from Group K, and R₂ is a sidechain of an amino acid selected from Group E, F and G, Y is --NHR₃ orOR₃, R₃ is hydrogen, C₁₋₄ straight or branched alkyl, phenyl, benzyl,cyclohexyl or cyclohexylmethyl,wherein Groups A, B, C, D, E, F, G and Kare as follows: GroupA: Lys and Arg B: Glu, Asp C: Ser, Thr, Gln, Asn,Cys, His D: Pro, Ind E: Ala, Leu, Ile, Val, n-Val Met, n-Leu andN-methyl derivatives F: Phe, Tyr, Trp, Nal (1), and N-methyl derivativesG: Gly, Sar K: Acetyl (Ac), Succinyl (Suc), Benzoyl (Bz),t-Butyloxycarbonyl (Boc), Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS),Isovaleryl (Iva), Methoxysuccinyl (MeOSuc), 1-Adamantanesuiphonyl(AdSO₂), 1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl (2-CBZ) and suchother terminal amino protecting groups which are functionally equivalentthereto.
 21. A compound of claim 20 having the formulaeBz-Phe CF₂-Gly!Pro-OH, or Bz-Phe-CF₂ -CO-Pro-OH.
 22. A compound useful forinhibiting enkephalinase of the formula ##STR86## the hydrates thereof,and the pharmaceutically acceptable salts thereof whereinX is X₂ whereinX₂ is ##STR87## R₄ is a side chain from an amino acid selected fromGroup E or F, R₅ is selected from Groups E or F or zero with the provisothat when R₅ zero, Y is NH₂, and Y is NH₂ or OH, R₁ is -P₂ -P₃, with P₂being Gly and P₃ being selected from Group F or is deleted, and R₂ isthe side chain of Glywherein Groups E and F are as follows: GroupE: Ala,Leu, Ile, Val, n-Val, Met, n-Leu and N-methyl derivatives F: Phe, Tyr,Trp, Nal (1), and N-methyl derivatives.
 23. A compound of claim 22selected from the group consisting ofTyr-Gly-Gly CF₂ -Phe!Met-OH,Tyr-Gly-Gly CF₂ -Phe!LeuNH₂, and H-Tyr-Gly-Gly-CF₂ -CO-Leu-OH.
 24. Acompound useful as an inhibitors of pseudomonas elastase of the formula##STR88## the hydrates thereof, and the pharmaceutically acceptablesalts thereof whereinX is X₂ wherein X₂ is ##STR89## R₄ is a side chainof an amino acid selected from Groups E and F, R₅ is selected fromGroups E and G, and Y is NH₂, R₁ is -P₂ -P_(g) with P₂ being selectedfrom Group E, P_(g) is selected from Group K, R₂ is a side chain of anamino acid selected from Groups E and Gwherein Groups E, F, G and K areas follows: GroupE: Ala, Leu, Ile, Val, n-Val, Met, n-Leu and N-methylderivatives F: Phe, Tyr, Trp, Nal (1), and N-methyl derivatives G: Gly,Sar K: Acetyl (Ac), Succinyl (Suc), Benzoyl (Bz), t-Butyloxycarbonyl(Boc), Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva),Methoxysuccinyl (MeOSuc), 1-Adamantanesulphonyl (AdSO₂),1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl (2-CBZ) and such otherterminal amino protecting groups which are functionally equivalentthereto.
 25. A compound of claim 24 having the formulaeMeOSuc-Ala-AlaCF₂ -Ile!Ala-NH₂.
 26. A compound useful for inhibiting leucineaminopeptidase of the formula ##STR90## the hydrates thereof, and thepharmaceutically acceptable salts thereof whereinX is X₁ or X₂ whereinX₁ is --CF₃, --CF₂ H, --CO₂ R₃ or --CONHR₃, X₂ is ##STR91## R₄ is a sidechain of an amino acid selected from any Group except K, R₅ is any groupexcept K, and Y is NH₂, R₁ is hydrogen or K, R₂ is a side chain of anamino acid selected from Groups A, B, E, F and J R₃ is hydrogen, C₁₋₄straight or branched alkyl, phenyl, benzyl, cyclohexyl orcyclohexylmethyl,wherein Groups A, B, C, D, E, F, G, J and K are asfollows: GroupA: Lys and Arg B: Glu, Asp C: Ser, Thr, Gln, Asn, Cys, HisD: Pro, Ind E: Ala, Leu, Ile, Val, n-Val, Met, n-Leu and N-methylderivatives F: Phe, Tyr, Trp, Nal (1), and N-methyl derivatives G: Gly,Sar J:--NHCH(--C═O)--CH₂ Φ(ρ-)NHC(═NH)--NH₂ (J-1), --NHCH(--C═O)--CH₂Φ(ρ-)C(═NH)--NH₂ (J-2), --NHCH(--C═O)--ΦCH₂ NHC(═NH)--NH₂ (J-3), and--NHCH(--C═O)--ΦCH₂ C(═NH)--NH₂ (J-4) with Φ representing phenyl, K:Acetyl (Ac), Succinyl (Suc), Benzoyl (Bz), t-Butyloxycarbonyl (Boc),Carbobenzoxy (CBZ), Tosyl(Ts), Dansyl (DNS), Isovaleryl (Iva),Methoxysuccinyl (MeOSuc), 1-Adamantanesulphonyl (AdSO₂),1-Adamantaneacetyl (AcAc), 2-Carboxybenzoyl (2-CBZ) and such otherterminal amino protecting groups which are functionally equivalentthereto.
 27. A compound of claim 26 selected from the group consistingofH-Leu-CHF₂, H-Arg-CF₃, H-(p-gua)Phe-CF₃, H-Leu-CF₃, H-Leu-COOH, H-LeuCF₂ -Ala!Ala-NH₂, H-Leu-COOMe, and.